All lawyers must understand basic concepts of deductive reasoning, especially the categorical and hypothetical syllogisms. They must understand inductive reasoning, with its twin facets of induced generalization and analogy. And they should have a mental blueprint on how to recognize formal and material fallacies.

Even though principled and sound in logic, an argument can still be wrong, but an unprincipled and unsound argument can never be right.

Value judgments reflecting the views of advocates and judges form the critical decisional points in the law. Rules of logic do not make these decisions; they are simply means to implement them. When these judgments are made, the formal reasoning process sets in to test the validity of the propositions constituting the argument.

A specific knowledge of the canons of reasoning enables one to discover more readily where the fallacy of a misleading argument lies. Without professing to guard us infallibly from error, the study of logic familiarizes us with the rules and canons to which correct reasoning processes must conform, and with the hidden fallacies and pitfalls to which such processes are commonly exposed.

It is the reasoning process—the fealty to the rules of logic—that gives legitimacy to judge-made law.

Common-law countries differ from the civil-law countries of Europe and Latin America where, in theory, the source of law is limited to Codes and written constitutions.

Case-by-case development allows experimentation because each rule is reevaluated in subsequent cases to determine if the rule did or does produce a fair result. If the rule operates unfairly, it can be modified.

Without a reasoning process adhering to rules of logic to support conclusions, judicial decisions would have been nothing more than decrees, orders and judicial fiat.

A judicial precedent attaches a specific legal consequence to a detailed set of facts in an adjudged case or judicial decision, which is then considered as furnishing the rule for the determination of a subsequent case involving identical or similar material facts and arising in the same court or a lower court in the judicial hierarchy.

It takes a long process of what Mr. Justice Miller used to call judicial inclusion and exclusion to justify you in being certain that you have hold of something so general, so universal, so capable of dealing with questions of that type that you can say here is an authoritative starting point for legal reasoning in all analogous cases.

When a specific holding of a case is suddenly anointed with the chrism of “principle,” it has a very real effect on the doctrine of stare decisis. There is always the danger that a commentator or a subsequent opinion writer, either in the same court or another, will elevate the decision’s naked holding to the dignity of a legal “principle,” and attribute to that single decision a precedential breadth never intended.

Case law stands or falls solely on the reasons articulated to justify it. There can be legislative fiat, but not judicial fiat. Reason justifies the legal rule emanating from a court decision. Where stops the reason, there stops the rule.

Cardozo rejected this analysis, describing it as an “extension of a maxim or a definition with relentless disregard of consequences to ‘a dryly logical extreme.’ The approximate and relative become the definite and absolute.”

Adhering to logical form and avoiding fallacies, we repeat for emphasis, is only a means to the ends of justice, but logical form and avoiding fallacies are nonetheless critical tools of argument. They are the implements of persuasion. They form the imprimatur that gives legitimacy and respect to judicial decisions.

This is because judge-made law, in the sense of either creating precepts or interpreting statutes and regulations, is affected by the facts of particular cases, as well as by social and philosophical considerations. Professor Levi says that “this change in the rules is the indispensable dynamic quality of law. It occurs because the scope of a rule of law, and therefore its meaning, depends upon a determination of what facts will be considered similar to those present when the rule was first announced. The finding of similarity or difference is the key step in the legal process.”

It is here when the judge makes a value judgment. At these times, the jural philosophy of the individual judge comes into play, consciously or otherwise, by means of a value judgment that places a greater weight on one competing principle than another.

Value judgments inhere throughout; it is not a mechanical process. Values do not form in a vacuum; their range depends always on factual limitations. Thus, judges’ decisions are governed by their beliefs about facts as well as abstract rules; the act of deciding involves both the determination of material facts and the determination of what rules are to be applied to the facts.

In the law, as well as in life itself, judging is the act of selecting and weighing facts and suggestions as they present themselves, as well as of deciding whether the alleged facts are really facts and whether an idea suggested is a sound idea or merely a fancy.

A rule of law (1) is viewed in combination with other rules by a process of inductive reasoning, (2) to form the major premise for a process of deductive reasoning in the next case, (3) leading to the conclusion of the deductive syllogism which forms the decision in the case, (4) which in turn takes the form of a new legal rule.

The ability to study law depends upon the power of seeing logical connections in the cases, of recognizing similarities and dissimilarities.

The line between a reasonable inference that may permissibly be drawn by a jury from basic facts in evidence and an impermissible speculation is not drawn by judicial idiosyncrasies. The line is drawn by the laws of logic. If there is an experience of logical probability that an ultimate fact will follow a stated narrative or historical fact, then the jury is given the opportunity to draw a conclusion because there is a reasonable probability that the conclusion flows from the proven facts.

When a trial court grants a directed verdict in a circumstantial evidence case, the court makes a legal determination that the narrative or historical matters in evidence allow no permissible inference of the ultimate fact urged by the opposing party.

In a criminal case, although certain portions of evidence may be introduced to present permissible inferences, the sum total must amount to a reasonable inference of the ultimate fact of defendant’s guilt. Thus, the ultimate issue in a civil case based on circumstantial evidence is the ability to draw a reasonable inference, and not a speculation, of liability.

The standards are stated in all their essentials in somewhat different language in Restatement of the Law where it is said that liability under this type of statue “involves a high degree of probability that substantial harm will result.” … Restatement, Torts § 500.

Direct evidence is said to be evidence which if believed proves the existence of the fact in issue without inference or presumption; while circumstantial evidence is evidence which, without going directly to prove the existence of a fact, gives rise to a logical inference that such fact does exist.

The fallacy of the state’s argument lies in its major premise that admissions are direct evidence. Some admissions are, such as where the defendant admits the commission of the crime. Some admissions, such as the making of a false statement, only raise an inference of guilt.

Without this evidence EEOC proved only that the employee was disadvantaged because he had PFB, not that he was disadvantaged because he was black.

Although a jury is entitled to draw reasonable inferences from circumstantial evidence, reasonable inferences themselves must be more than speculation and conjecture. Galloway v. United States, 319 U.S. 372 (1943). For example, in Daniels v. Twin Oaks Nursing Home, 692 F.2d 1321 (11th Cir. 1982), the court rejected as too speculative inferences that a nursing home was negligent and therefore liable for a resident’s wrongful death when he wandered off while under the nursing home’s care. Upholding the district court’s grant of judgment n.o.v., the court stated that, “a jury will not be allowed to engage in a degree of speculation and conjecture that renders its finding a guess or mere possibility. Such an inference is infirm because it is not based on the evidence.”

Inferences that the reports were understood as defamatory and that they caused or contributed to Sunward’s financial difficulties are here supported only by speculation and conjecture. The record is devoid of evidence that anyone ever understood the credit reports in the defamatory manner inferred by the plaintiff.

A belief is simply an assertion about a fact or law that we accept. It is something that we affirm, or at least acquiesce in, even though it is a matter of which we have no sure knowledge or proof. But it is something of which we are sufficiently confident to act upon. It is something we now accept as true.

In the law, our major proposition—called the major premise—must usually have the hallmark of legal authority, constitutional text, statute or case law.

In law there are no absolute truths like those established in mathematics. Lacking absolute truths, logical propositions merely express that which is likely to be true or false.

The categories used in the legal process must be left ambiguous in order to permit the infusion of new ideas.

Therefore it appears that the kind of reasoning involved in the legal process is one in which the classification changes as the classification is made. The rules change as the rules are applied.

Determining what is “reasonable” is closely related to the overarching process we call “reasoning,” a progression of thought based upon the logical relation between truths. … Reasoning involves recognizing a “link in actual things, that makes one thing the ground, warrant, evidence, for believing in something else.”

Arguments that have both valid or cogent reasoning and true premises are sound arguments. Thus, an argument fails to be sound if either (a) the reasoning it employs from premises to conclusion is not acceptable, or (b) one or more of its premises is false.

A sound argument is any deductive argument which is valid and which has only true premises.

While the last four words of both statements are identical (“I committed the crime”), the meaning of those four words is different and is determined by the context.

The fact that the defendant is permitted under our precedents to explain that information from or about the polygraph examination motivated him or her to make the statements does not dilute the requirement that redacting a statement must not alter significantly the meaning of the defendant’s actual statement in order to be introduced over an objection based on OEC 402 or OEC 403.

The logic of the law is neither all deductive nor all inductive.

This is a categorical syllogism, an argument having three propositions—two premises and a conclusion.

Formulating a generalization in the law, that is, enumerating a series of tight holdings of cases (legal rules) to create a generalized legal precept (legal principle), is at best a logic of probabilities. We accept the result, not because it is an absolute truth, like a proposition in mathematics, but because it gives our results a certain hue of credibility. The process is designed to yield workable and tested premises, rather than truths.

The inductive conclusion then becomes the major premise in a deductive argument to reach the conclusion urged upon the court.

A proper analogy should identify the number of respects in which the compared cases, or fact scenarios, resemble one another (let us call these resemblances positive analogies) and the number of respects in which they differ (negative analogies). In analogy, unlike the method of enumeration, the quantity of cases is not significant. Instead, what is important is relevancy—whether the compared facts resemble, or differ from, one another in relevant respects.

When we analyze or evaluate reasoning, however, we reverse the process; we begin with the conclusion, for it is in the conclusion that, as brief writers, brief readers, oral advocates and judges, we examine the quality of the reasoning and evaluate the soundness of the arguments.

Thus, a universal proposition (All offers in contract law) is described as containing a “distributed” subject term. A particular proposition (Some offers in contract law) has an “undistributed” subject term.

Syllogism: A syllogism is an argument containing premises and a conclusion.

A class is a collection of objects that have in common some specified characteristic. “Categorical propositions” are statements about classes.

Quantity of a proposition determines whether its subject term is distributed.

Quality of a proposition determines whether its predicate term is distributed.

The subject term of a universal proposition is said to be distributed. In our example, we speak of “any manufacturer” or “the vendor.” In each case, the assertion concerns all manufacturers and vendors in the stated class without restriction. Hence, the subject is distributed.

Because the proposition is affirmative, we know that the predicate (liability) is undistributed. That means that the proposition tells us something about a limited group of liable persons: the group that coincides with the subject group of manufacturers.

Most often the omitted premise is the major premise (All good girls get a star on their forehead) and is called an enthymeme of the First Order.

In formal argument, when one of the premises or the conclusion is not expressed, the argument is called an enthymeme.

A polysyllogism is a series of syllogisms in which the conclusion of one is a premise of the next.

The selection of a major premise, as we have emphasized before, is a value judgment. The advocate or the judge makes this value judgment. A choice is made. No unerring rules of logic dictate this important decision, which is the critical threshold, the prelude to the operation of the rules of logic.

The bottom line: The validity of a syllogism and the soundness of the argument’s structure deal only with relations between the premises. Validity deals only with form. It has absolutely nothing to do with content.

A capital offense is one that is punishable by death. In Florida, murder in the first degree is the only existing capital offense.

Often an alleged attack on the “reasoning” of the court is really a disagreement with the value judgment implicit in the court’s major premise—a disagreement with the court’s selection and interpretation of the applicable legal precept.

Criticism of court opinions would be more professional, briefs more clear, points of friction between litigants earlier identified and accommodated, if resort to the cosmos of “reasoning” were minimized, and attention directed instead to the precise components of that cosmos.

Three terms (major, middle and minor) must be involved in every valid syllogism. Any categorical syllogism that contains more than three terms is said to commit the formal Fallacy of Four Terms (quaternio terminorem) (see Chapter 10).

Because to distribute a term is to take in its whole extent, a distributed term refers to every member contained under the term.

Certainly, all those who have framed written constitutions contemplate them as forming the fundamental and paramount law of the nation, and consequently, the theory of every such government must be that an act of the legislature, repugnant to the constitution, is void.

It is, emphatically, the province and duty of the judicial department, to say what the law is. Those who apply the rule to particular cases, must of necessity expound and interpret that rule.

When they tax the chartered institutions of the states, they tax their constituents; and these taxes must be uniform. But when a state taxes the operations of the government of the United States, it acts upon institutions created, not by their own constituents, but by people over whom they claim no control.

The question is simply this: can a Negro whose ancestors were imported into this country and sold as slaves, become a member of the political community formed and brought into existence by the Constitution of the United States, and as such become entitled to all the rights, and privileges, and immunities, guaranteed by that instrument to the citizen. One of these rights is the privilege of suing in a court of the United States in the cases specified in the Constitution.

It has already been shown that in five of the thirteen original states, colored persons then possessed the elective franchise, and were among those by whom the Constitution was ordained and established.

To separate [children in grade and high schools] from others of similar age and qualifications solely because of their race generates a feeling of inferiority as to their status in the community that may affect their hearts and minds in a way unlikely ever to be undone.

We conclude that in the field of public education the doctrine of “separate but equal” has no place. Separate educational facilities are inherently unequal.

Various guarantees create zones of privacy. … The Ninth Amendment provides: “The enumeration of the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.”

Such a law cannot stand in light of the familiar principle, so often applied by this Court, that a “governmental purpose to control or prevent activities constitutionally subject to state regulation may not be achieved by means which sweep unnecessarily broadly and thereby invade the area of protected freedoms” [citation omitted].

The test traditionally applied in the area of social and economic legislation is whether or not a law such as that challenged has a rational relation to a valid state objective….

Proscriptions against that conduct have ancient roots…. Sodomy was a criminal offense at common law and was forbidden by the laws of the original thirteen States when they ratified the Bill of Rights. In 1868, when the Fourteenth Amendment was ratified, all but 5 of the 37 States in the Union had criminal sodomy laws.

Our action today makes explicit: federal racial classifications, like those of a State, must serve a compelling governmental interest, and must be narrowly tailored to further that interest.

Inductive generalization: Also known as induction by enumeration, this is the process of arriving at general or universal propositions from the particular facts of experience, relying on the principle of induction. The premises are instances of certain facts with accompanying legal consequences which repeatedly accompany one another (legal rules) from which it is concluded that the legal consequence will always accompany the facts (legal principle).

Analogy: This is reasoning from the particular to the particular, and this is technically distinguished from reasoning from the particular to the general. To draw an analogy between at least two entities is to indicate one or more respects in which they are similar. It is to argue that the legal consequence attached to one set of particular facts may apply to a different set of particular facts because of similarities in the two sets of facts.

It becomes apparent, however, that an induction by enumeration is very similar to an argument by analogy. They differ only in the breadth of their conclusions. By enumeration, you induce a generalization; by analogy, you induce a particular.

Unlike in science, however, in law we do not assert that our conclusion is true; we represent only that it is more probably true than not.

Inductive generalization underlies the development of the common law. From many specific case holdings, we reach a generalized proposition.

The greater the number of cases in the cumulative experience, the higher the degree of probability in the conclusion. The various instances of fact A and legal consequence B are called confirming instances of the causal relationship between fact A and legal consequence B. The greater number of confirming instances, the higher the probability of the conclusion.

J. S. Mill reduced it to a formula: Two things resemble each other in one or more respects; a certain proposition is true of one; therefore it is true of the other.5 In legal analogies, we may have two cases which resemble each other in a great many properties, and we infer that some additional property in one will be found in the other.

Plaintiff’s lawyer may argue that the historical event or entity “A”—in law, a putative precedent—bears many resemblances to the case at bar, “B.” The opponent will argue that although the facts in “A” and “B” are similar in some respects, this does not mean that those similarities are material and therefore relevant, or that the cases are similar in other respects; he or she will argue that a false analogy is present.

Analogies can be considered the most important aspect of the study and practice of law. It is the method by which putative precedents are subjected to the acid test of searching analysis. It is the method to determine whether factual differences contained in the case at bar and those of the case compared are material or irrelevant.

In the language of the logicians, the positive resemblances in the facts do not outweigh the negative resemblances in the compared factual scenarios.

However, the legal use of analogy is more like the scientific use than the ordinary use in the following sense: that the claim that X and Y are analogous is made with respect to some theoretical basis. The appeal is not (at least wholly) to perception. Rather the theoretical basis (in law, certain conventional rules of relevance established as precedents) gives us a decision procedure for determining whether or not cases X and Y are indeed analogous.

It permits the law to move with the times, as aptly illustrated by Cardozo’s comparison of the automobile wheels to those of the stagecoach. It is the counter-agent of attempts to embalm legal precepts. It permits the elasticity necessary in order to hearken to the adage: “The law must be stable, but it must not stand still.”

In my opinion it should now be recognized that a manufacturer incurs an absolute liability when an article that he has placed on the market, knowing that it is to be used without inspection, proves to have a defect that causes injury to human beings. … Even if there is no negligence, however, public policy demands that responsibility be fixed wherever it will most effectively reduce the hazards to life and health inherent in defective products that reach the market.

The liability of an innkeeper extends only to goods put in his charge as keeper of a public house, and does not attach to a carrier who has no house and is engaged only in the business of transportation.

The principle upon which innkeepers are charged by the common law as insurer of the money or personal effects of their guests originated in public policy. It was deemed to be a sound and necessary rule that this class of persons should be subjected to a high degree of responsibility in cases where an extra-ordinary confidence is necessarily reposed in them, and where great temptation to fraud and danger of plunder exists by reason of the peculiar relations of the parties….

A steamer carrying passengers upon the water, and furnishing them with rooms and entertainment is, for all practical purposes, a floating inn, and hence the duties which the proprietors owe to their charge ought to be the same.

As the majority opinion points out, the churches were to pay nothing for the directories. Those institutions were out the value of whatever their services (no pun intended) might have been worth, but there was no attempt whatever to produce evidence of the value of the efforts they expanded in getting their constituent families rounded up for the photography sessions. Nor was any attempt made by the State to show the difference between the value of what the church members received (the photographs) and what they were promised (the photographs plus the “free” directories).

As Munroe Smith stated, “The rules and principles of case law have never been treated as final truths, but as working hypotheses, continually retested in those great laboratories of the law, the courts of justice.”

It rests upon the implied premise, which we think false, that on the one hand, the female is viewed as a pure, delicate and vulnerable creature who must be protected from exposure to criminal influences; and on the other, as a brazen temptress, from whose seductive blandishments the innocent male must be protected. Every woman is either Eve or Little Eva—and either way, she loses …. We have only to look at our own female secretaries and female law clerks to conclude than an intimate business relationship, including traveling on circuit, between persons of different sex presents no “appearance of impropriety” in the current age, graduated as we are from Victorian attitudes.

A generalization “based on the cumulative experience of the judiciary,” is simply an elegant way of describing an enumeration of instances. And “seeking … to identify the relevant characteristics that are common [among cases]” is no more than analogy. You will also note that the process described in the paragraph above is a classic description of inductive reasoning.

In all the decisions that have been analysed a duty of care has been held to exist wherever the conduct and the relationship possessed each of the characteristics A, B, C, D, etc., and has not so far been found to exist when any of these characteristics were absent.

For the second stage, which is deductive and analytical, that proposition is converted to: “In all cases where the conduct and relationship possess each of the characteristics A, B, C, D, etc., a duty of care arises.” The conduct and relationship involved in the case for decision is then analysed to ascertain whether they possess each of these characteristics. If they do the conclusion follows that a duty of care does arise in the case for decision.

First, the actual damage sustained by the plaintiff was the direct consequence of a tortious act done with conscious volition by a third party responsible in law for his own acts and this act was interposed between the act of the defendant complained of and the sustention of damage by the plaintiff.

It bears mention that here Lord Diplock had to make a value judgment as to what facts are really relevant, that is to say, what are the relevant resemblances in the facts and the relevant differences.

By examining several overarching common-law principles relating to the acts of public authorities, he was able to show how the resemblances outweighed the differences.

The issue and the rule/holding are interrelated. Issues should be stated so that the holding could be expressed as a “yes” or a “no.”

Think of the major premise that should control. In all cases in which “X” set of facts appeared, courts applied “Y” rule of law and drew “Z” conclusion.

The answer to your professor’s hypothetical questions posed in the Socratic method will depend upon choices (i.e., which major premise the attorneys, judge or jury adopt), value judgments (i.e., Is society, or are the courts, prepared to impose tort liability in strict-products liability cases on those most able to pay regardless of proof of wrongdoing?), personal biases in interpreting rules of law and identifying relevant facts (i.e., Is race a relevant fact in this case?).

Reflective thinking makes us look at links. It requires that we see a connection from the known to the unknown. We reach a conclusion in one set of facts by deciding what inferences may be drawn from other sets.

To analyze different factual scenarios is to engage in inductive reasoning, a reasoning based on probabilities. The conclusion emerging from induction then serves as a premise—major or minor—in the deductive process that follows.

This court finds that the undisputed evidence established that Hinman is married to an Asian-American woman who was described as being strong willed. The court finds that this fact evidences the fallacy of the Plaintiff’s theory that Hinman was biased against Asian-American women and expected them to be meek and subservient.

Notwithstanding its popular or lay use, exemplified by the foregoing excerpts, logicians and the legal profession generally use the term “fallacy” in a narrower sense to describe a type of incorrect argument, rather than a description of falsity or error in a statement.

A formal fallacy is any violation of any of the six rules of the categorical syllogism or the rules of the hypothetical or disjunctive-alternative syllogism. It is an argument whose conclusion could be false even if all its premises are true. It can be detected merely by examining the form (hence its name) or structure of the argument.

An informal fallacy is one that cannot be detected merely by examining the form of the argument but must be detected in some other way. It is any other argument that does not properly establish the supported conclusion. An argument contains an informal fallacy when at least one of its premises is not true, or when the rules of inference are not properly respected.

Fallacies are dangerous because they are false conclusions or interpretations resulting from thinking processes that claim or appear to be valid, but fail to conform to the requirements of logic.8 A fallacy can, therefore, be defined as “any argument that seems conclusive to the normal mind but that proves, upon examination, not to establish the alleged conclusion,”9 or more succinctly, a form of argument that seems to be correct but that proves upon examination not to be so.

In disjunctive arguments the fallacy consists of the imperfect disjunctive, either in the form of missing disjuncts or non-exclusivity (when one assumes that affirming one disjunct means that the other must be false when in fact it is possible for both to be true).

This is a breach of the first rule which insists that a categorical syllogism must contain only three terms, each of which is used in the same sense throughout the argument.

Appellants’ contention that the statute is overbroad is founded on the general rule that a statute is tainted if the conduct it prohibits includes protected activity as well as criminal conduct.

The rule states that in a valid categorical syllogism, the middle term must be distributed in at least one of the premises.

To put it in a formula, this fallacy occurs whenever it is argued that because x and y belong to the same class or possess a common property, they are identical.

I believe the Court has fallen into the logical fallacy sometimes known as the fallacy of the undistributed middle, because it has failed to examine the supposedly shared principle between admission of prior crimes related to guilt and admission in connection with recidivist statutes. That the admission in both situations may serve a valid purpose does not demonstrate that the former practice justifies the latter any more than the fact that men and dogs are animals means that men and dogs are the same in all respects.

In a formally valid categorical syllogism, the middle term must be distributed in at least one of the premises.

“A valid standard-form categorical syllogism must contain exactly three terms, each of which is used in the same sense throughout the argument.”

The arguments contain material fallacies, that is, errors or evasions that appear only through an analysis of the meaning of the terms, rather than an analysis of the logical form.

There is nothing linking Mr. Mordelt’s presence in New Orleans to the contract of sale. By attempting to link these two occurrences simply because of their connection to the New Orleans convention, Amusement Equipment commits the logical fallacy of the “undistributed middle.”

That both the contract and Mordelt’s visit pertained to the trade show does not mean that the two were connected to each other.

This argument begs the Court to fall into the logical fallacy of the undistributed middle. As a matter of logic, the fact that some SL1001 are noninfringing because they are made, used and sold outside the United States does not mean that all SL1001 exciters are noninfringing no matter where they are made, used or sold, any more than the fact that because fish cannot fly and penguins cannot fly, penguins must therefore be fish.

As Johnson stated, they based their initial decisions as to which travelers to approach upon a series of allegedly suspicious characteristics and circumstances, as contained in the now-familiar “drug courier profile,” supplemented by the airport squad’s own prior experiences. It may be fairly said as to all of the officers’ bases of “suspicion” that, although they may indeed be characteristic of those who carry narcotics, they are at least equally, and usually far more frequently, consistent with complete innocence.

In a valid standard-form categorical syllogism, if either term is distributed in the conclusion, then it must be distributed in the premises.

When the major term in the major premise is undistributed but is distributed in the conclusion, this is called the Fallacy of the Illicit Process of the Major Term (or, familiarly, the Illicit Major).

When the minor term is undistributed in the minor premise but distributed in the conclusion, the argument commits the Fallacy of the Illicit Process of the Minor Term (the Illicit Minor).

Here the contrast between Congress’s mandate in one context with its silence in another suggests not a prohibition but simply a decision not to mandate any solution in the second context, i.e., to leave the question to the agency discretion.

If both premises are negative, we cannot determine anything regarding their relation to one another.

This type of reasoning is unacceptable because of the difficulty in sustaining a factual proposition merely by negative evidence.

The appellant is taking the universal negative proposition, “No motile sperm are pre-11:11 (in terms of ejaculation)—No A is B—and attempting to infer the so-called contrapositive of that proposition, to wit, No non-motile sperm are post 11:11—(in purer terms, non-pre 11:11)—No non-A is non-B. By the laws of logic, however, the inference of the contrapositive is invalid where the starting proposition, as in the case at bar, is a universal negative.6

Therefore, because the court will not entertain constitutional questions predicated upon inadequate factual records, Taunt v. Moegle, 344 Mich. 683, 686, 75 N.W. 2d 48 (1956), the constitutionality of 1993 PA 362 is not properly addressed in the context of defendant Noah Webster Acadeny.

It is entirely consistent with the major premise to suppose that there are other invalidating circumstances (other possible antecedents) which will give the same consequent, e.g., undue influence over the testator in drafting his will. Thus the denial of this particular circumstance (the insanity of the testator) does not warrant a denial of the consequent (that the will is invalid).

Here again the conclusion goes beyond the major premise by presupposing that the only condition under which a will can be invalid is that the testator was insane. Other conditions can invalidate a will, e.g., no signature, no witnesses.

A method of determining rates, or divisions thereof, is unjust and unreasonable if the result reached does not afford a compensatory return.

The proposition that “A implies B” is not the equivalent of “non-A implies non-B,” and neither proposition follows logically from the other. The process of inferring one from the other is known as “the fallacy of denying the antecedent.”

This argument commits the classical fallacy known as “denying the antecedent of a conditional statement.” This fallacy is committed when a statement in the conditional form “if P then Q” is taken to imply “if not P, then not Q.”

The indispensable prerequisite to a valid conclusion in the case of a disjunctive syllogism is that the major premise express a complete disjunction in the sense that its alternative terms be mutually exclusive and collectively exhaustive. They admit of no third possible alternative.

The real problem in law consists in creating proper premises, in discovering the relations enumerated in the major premise. Errors are most likely to arise in formulating the major premise. It is essential that the disjunctive members shall be exhaustively enumerated, and also that they shall exclude one another. In the law we all can slip into the fallacy of the missing disjuncts when we do not include all the alternatives in the major premise.

A categorical proposition expresses no condition. Hypothetical propositions present their conditions as hypotheses (If the conveyance of real estate is oral, it is invalid). Disjunctive propositions present their conditions as alternatives.

Fallacies arise in the missing disjuncts: failure to include all possibilities or alternatives in the major premise.

Fallacies also arise in the nonexclusivity of the disjuncts. “All personal injury complaints for negligence must be brought within the two years of the automobile collision or the claim will be barred,” fails to contemplate the tolling of the limitations period because of a late discovery that the injury occurred. Accordingly, the disjuncts are not mutually exclusive.

Regardless of the issue on which rehearing en banc was granted, the court is deciding this criminal case and no other. Instead of speculating about a string of successful prosecutions in other cases, we must focus on a relatively short string of prosecutions—the successful trial of Standefer preceded by the unsuccessful trial of Niederberger.

If this was an issue raised by the appellant, the majority would have (and has on numerous occasions) summarily dismissed this contention by citing the well-worn and well-established rule that there was “no objection at trial, thus nothing is presented for review.” For some unexplained reason the majority fails to apply that same rule of law to the State, in its appeal before this Court.

The majority attempts to disprove point B (legislative history of enforcement of franking laws), instead of disproving point A (Postal Service enforcement), which is the real issue at stake. Logicians call this technique the fallacy of irrelevance, ignoratio elenchi.

The question under consideration, however, is not whether Title VII was so amended but whether, on the strength of a mere conclusory allegation of discrimination, the EEOC is permitted the kind of intrusion into the tenure review process it seeks here.

The acceptability of the argumentum ad misericordiam in equity and criminal sentencing is explained by the nature of the decisions to be reached in those contexts. Both equity cases and discretionary sentencing decisions involve attempts to do justice and are thus different in nature from questions of fact or law. Doing justice requires looking at hardships that already exist and deciding whether imposing a penalty or a remedy would cause a greater hardship in a particular case than normally accompanies that sentence or remedy. In such cases, an argumentum ad misericordiam is not a fallacy because it is actually relevant to the decision.

However, if the question under consideration is a factual issue—whether the defendant committed the crime charged or whether the parties agreed to a contract—an appeal to pity is irrelevant; it simply deflects attention away from the facts.

When the source of the law is not significant per se, the only effect of citation is rhetorical. In formal logic the device is known as argumentum ad verecundiam, playing upon the prestige of the source.

This fallacy shifts an argument from the point being discussed (ad rem) to irrelevant personal characteristics of an opponent (ad hominem). Instead of addressing the issue presented by an opponent, this argument makes the opponent the issue. It shifts attention from the argument to the arguer; instead of disproving the substance of what is asserted, the argument attacks the person who made the assertion.

Another proper use of the ad hominem is in receiving expert witness testimony where the witness simply states a conclusion after establishing the predicate facts. It is fair game to attack these witnesses by questioning their expertise or incentives for testifying.

The personal attacks concerning Hagan’s marital problems and Callinan’s financial circumstances bore no relationship, certainly none which could be considered reasonable, to the question whether the Poly High School property should be rezoned, the only subject before the voters.

The popular acceptance of a policy or practice does not show it to be wise; the fact that a great many people hold to a given opinion does not prove it to be true. The test is whether the believers are expert or at least competent in the field, or on the particular proposition believed.

The majority unnecessarily and gratuitously injects into its analysis an inflammatory hypothetical—not present or suggested in this case: “Posting a sign, for example, that reads ‘No Blacks Need Apply’ or that reads ‘No Union Members Need Apply’ and that succeeds in its objectives is just as effective (and just as offending) a method of discrimination as a point-blank refusal to hire ….” This of course is the classic informal fallacy of argumentum ad populum, an appeal to strong feelings of the multitude.

It is revolting to have no better reason for a rule of law than that so it was laid down in the time of Henry IV. It is still more revolting if the grounds upon which it was laid down have vanished long since, and the rule simply persists from blind imitation of the past.

The argumentum ad antiquitam may not be a fallacy in constitutional law.

Not surprisingly, there exists the counter-fallacy of argumentum ad novitam or an appeal to novelty, modernity, current mores or youth.

Standing alone, historical patterns cannot justify contemporary violations of constitutional guarantees, but there is far more here than simply historical patterns. In this context, historical evidence sheds light not only on what the draftsmen intended the Establishment Clause to mean, but also on how they thought that Clause applied to the practice authorized by the First Congress—their actions reveal their intent.

In view of the judicial power to preserve the integrity of a zoning ordinance, by mandatory injunction if necessary, we do not foresee that money will be invested or properties substantially altered without first legally testing the zoning ordinance.

Defendant implicitly raises the ad terrorem argument that allowing a strict tort liability theory to obtain in this case will “open the flood gates” to disastrous litigation which will ultimately thwart the fulfillment of the hospitals’ worthy mission by drainage of their funds for purposes other than those intended. Our answer to this contention is that (paraphrasing what we observed [before]) we do not believe in this present day and age, when the operation of eleemosynary hospitals constitutes one of the biggest businesses in this country, that hospital immunity can be justified on the protection-of-the-funds theory. The concept of strict liability in tort logically, and we think, reasonably, dictates that an entity which distributes a defective product for human consumption, whether for profit or not, should legally bear the consequences of injury caused thereby, rather than allowing such loss to fall upon the individual consumer who is entirely without fault.

New knowledge must be derived from some measure of knowledge. We cannot affirm knowledge from a state of ignorance (lack of proof). Knowledge cannot be derived from ignorance.

New drugs are tested for safety. The absence of any toxic effect is taken to be evidence. When a security investigation reveals no instances of improper conduct, it would be wrong to conclude that the investigation left us ignorant. … Professors Copi and Burgess-Jackson suggest that the following factors be kept in mind: (a) How many individuals are attempting the proof; (b) whether those individuals are experts, or at least competent, on the matter at hand; (c) whether those attempting the proof are motivated (have an incentive) to prove the matter; (d) whether those attempting the proof have the technology and other resources necessary to conduct the inquiry and make the proof; (e) for how long a time the individuals have tried to prove the proposition.

It can be said that a classic appeal to ignorance is accepted in the law: in meeting one’s burden of proof in a trial. In criminal cases, for example, the defendant is presumed innocent unless the prosecution proves guilt beyond a reasonable doubt.

To apply the general hearsay rule to these exceptions is to commit the fallacy of accident or dicto simpliciter.

The converse fallacy of accident is the reverse of dicto simpliciter. It occurs when we move carelessly or too quickly to a generalization. It occurs when we construct a general rule from an inadequate number of incidents. … The fallacy appears when one or two decisions are used to make a quantum leap to a conclusion that these decisions form a rule with general application.

The classic example was a massive effort by the Literary Digest to forecast the Presidential election of 1936. More than 10,000,000 ballots were sent out. Something like 2,367,523 came back, mostly marked for Alf Landon. The poll predicted 370 electoral votes for the Republican candidate, and 161 for Franklin Delano Roosevelt, the Democrat. In the real election, Roosevelt won 523 electoral votes, with Landon receiving eight. What went wrong? The Digest, it seems, sent ballots to addresses collected from the subscription lists of magazines, and also from telephone directories and automobile registration lists. But magazines, telephones and automobiles were not randomly distributed among the American population in 1936.

To avoid the fallacy of accident, a court must consider whether the facts of the case sub judice can be distinguished from the situations that gave rise to the general rule. Courts regularly extend rules to encompass a wider variety of situations, thereby creating a more general rule. Such generalization is hasty only if the original rule was based on specifics not present in the case to which the rule is being extended.

If Prosser means to say that an isolated act of negligence—on the highway or in the home—destroys the faith, trust and tranquillity of the marriage, his statement is simply incredible.

The logical fallacy of Converse Accident (hasty generalization) is the reverse. It occurs when a person erroneously creates a general rule from observing too few cases.

The right to appeal is a statutory right, not a constitutional right. The Supreme Court has repeatedly recognized that a defendant may waive constitutional rights as part of a plea bargaining agreement. It follows that a defendant may also waive statutory rights, including the right to appeal.

[N]or is it reasonable to conclude, merely because one event, in one instance, precedes another, that therefore the one is the cause, the other the effect. Their conjunction may be arbitrary and casual.

The mere chronological sequence of events does not establish a causal connection.

Logicians describe one process of reaching an ultimate fact from insufficient basic facts as the false cause or post hoc fallacy. The fallacy consists of reasoning from sequence to consequence, that is, assuming a causal connection between two events merely because one follows the other. For this reason the fallacy is often referred to as that of post hoc ergo propter hoc (after this and therefore in consequence of this), an expression which itself explains the nature of the error.

This form of reasoning represents a logical fallacy known as the post hoc ergo propter hoc (after this and therefore because of this) fallacy.

The difference between the post hoc and the non sequitur fallacies is that the post hoc fallacy lacks a causal connection; the non sequitur fallacy lacks a logical connection.

The conclusion is a non sequitur.

On appeal, the city raises two contentions of error. The second is that the city strictly complied with the procedural requirements of the state enabling statute—Chapter 89 R.S. Mo. 1986—and therefore the refusal to rezone cannot be unreasonable. That is a non sequitur. Such a conclusion would render court review of zoning decisions illusory and nonexistent. A court would be restricted to examination only if the procedure followed and would be unable to set aside zoning determinations no matter how arbitrary, capricious, unreasonable or confiscatory if the statutory procedures were followed.

Zelis complained that entry of judgment in this action was improper because there are other lawsuits still pending between the parties; this contention is a non sequitur since the existence of other pending actions does not affect the finality of this one, or alter the fact that Zelis stipulated to entry of judgment in this action.

The fallacy of the compound (or complex or multiple) question occurs when an argument is phrased as a single question rather than the two or more separate questions actually in the interrogatory. Several questions are combined in such a manner as to place the person who responds in a self-incriminating position. When the question is complex and all aspects are to be denied, they should be denied individually. To require a single answer to the final part of the complex question (Now, answer yes or no!) often may lead to the unwarranted assumption of the truth of another matter or conclusion hidden in the question.

This fallacy is really a first-class rascal because it sneaks up on us so often. It is a species of question-begging that assumes as true what is to be proved. It is to assume the truth of what one seeks to prove in the effort to prove it.

I can think of no single fault that has done more to confuse the law and to disseminate litigation. One would suppose that so transparent a logical vice would be easily detected; but the offenders pass in troops before our eyes, bearing great names and distinguished titles.

The truth is that we are all sinners; nobody’s record is clean and indeed it is only fair to say that much of the very texture of the law invites us to sin, for it so often holds out to us, as though they were objective standards, terms like “reasonable care,” “due notice,” “reasonable restraint,” which are no more than signals that the dispute is to be decided with moderation and without disregard of any of the interests at stake.

This was classic petitio principii. The Court openly assumed that the First Amendment was safeguarded by the due process clause of the Fourteenth Amendment. There was no rational discourse. No syllogism with major premise or minor premise. Merely a conclusion that was candidly assumed.

The presence of subject matter jurisdiction is a discrete and primary issue in each case presented to a federal court, unlike a state court.

The effect on commerce is both jurisdictional and substantive in a Hobbs Act prosecution, but the two inquiries are separate and distinct.

Establishing that buyers purchase products A and B from the seller does not establish that the seller ties the sale of product A to the purchase of product B. It merely establishes that buyers purchase products A and B from the seller.

This reasoning succumbs to the fallacy of petitio principii, commonly identified as circular reasoning or begging the question. Thus, a fetus is not considered to have certain legal rights because it has not been born. No reason in logic is given why these rights could not be ascribed to a child before birth, only that they are not. When the question presented is whether or not legal rights should be ascribed, that question cannot be answered simply by stating that the law does not do so.

The refusal to charge this request obviously eliminated from the case all consideration by the jury of the question of provocation to which we have adverted, and which was properly a subject for their consideration, as a basis for mitigation of damages. The doctrine which requires the court to submit to the jury the question of provocation, in cases where the complaining party insists upon punitive or exemplary damages, is settled beyond controversy by the great trend of adjudication in this country.

Categorical syllogism Rule One not only insists that the argument contain exactly three terms, but that each term be used in the same sense throughout the argument. When different senses are utilized, linguistic fallacies occur. Some of these are fallacies of ambiguity (equivocation and amphibology). Others are known as fallacies of composition, division and vicious abstraction.

When we confuse the several meanings of a word or phrase, we use the word or phrase equivocally. When we do this in the context of an argument, we commit the fallacy of equivocation.

It is important to keep in mind Rule One of the categorical syllogism: A valid categorical syllogism must contain exactly three terms, each of which is used in the same sense throughout the argument.

It equates “conspiracy” as a concept of substantive criminal law, governing who may be punished for which acts, with “conspiracy” as part of an evidentiary principle, and burdens the latter with all of the theoretical limitations and formal requirements of the former. The two are not the same, though it is likely that any provable criminal conspiracy will satisfy the requirements of the evidentiary rule.

In equivocation, ambiguity comes from changing meanings of the word; in amphibology, ambiguity comes from the grammatical structure. The double meaning lies not in the word but in the syntax or grammatical construction of a sentence or sentences.

Amphibology differs from equivocation in two important respects. Although amphibology pertains to the entire argument, equivocation is limited to single words or phrases; the entire argument is susceptible to a two-fold interpretation due to its structure, not to any misuse on the part of the debater.

In the law the confusion is usually an inference that proceeds from the specific to the general and argues from attributes of parts of the whole to attributes of the whole itself.

“Italy has the best pasta in the world. Therefore, if you eat pasta at Giovanni’s in Rome you will eat the best dish of pasta in the world.”

The Board’s initial contention is that, although this court has disagreed with it on the issues of comity and appropriate hospital bargaining units, we must nevertheless enforce the Board order because it is a “reasonably defensible” construction of the National Labor Relations Act. We reject this attempt to emasculate judicial review of NLRB orders by a resort to an isolated phrase taken out of its context in the Supreme Court’s opinion—a “fallacy of vicious abstraction.”

The construction put on a statute by the agency charged with administering it is entitled to deference by the courts, and ordinarily that construction will be affirmed if it has a “reasonable basis in law,” but “[t]he deference owed to an expert tribunal cannot be allowed to slip into a judicial inertia which results in the unauthorized assumption by an agency of major policy decisions properly made by Congress.”

It has been recognized that in [Sherman Act] § 2 cases identification of the relevant geographic market is a matter of analyzing competition. “The geographic market encompasses the area in which the defendant effectively competes with other … businesses for the distribution of the relevant product.” It is “defined in terms of where buyers can turn for alternative sources of supply.” The definition of the relevant geographic market, therefore, is a question of fact to be determined in the context of each case in acknowledgment of the commercial realties of the industry under consideration….

What was before the Supreme Court in Otter Tail is not the issue presently before us: whether determination of the relevant geographic market was for the court or for the jury. Although in Otter Tail the relevant geographic market coincided with the aggregate of the towns in the defendant’s service area, there is in that opinion no indication that its definition was achieved as a matter of law.

By dipping into the Otter Tail opinion and picking out a single sentence, Lansdale is guilty of the common fallacy of vicious abstraction—the removal of a statement from its context, thereby changing its intended meaning.

The successive portions of a reflective thought grow out of one another and support one another; they do not come and go in a medley. Each phase is a step from something to something. The stream or flow becomes a train or chain. There are in any reflective thought definite units that are linked together to a common end.

If A has been found to be liable in set of circumstances (facts) B, we have to decide, often without an exact precedent to guide us, whether A is also liable if B obtains plus or minus circumstance C. To do this we determine if the additional circumstance is material.

When Browder came down, it was recognized that, as a matter of law, the entire doctrine of separate but equal was overruled without being limited to the reasons stated in Brown: the special and particular problems of segregated education, circumstance B. Changing social and judicial perspectives had rendered circumstance B—the driving force for the Brown decision, the necessity of giving children a proper education—now immaterial to the overarching problem of racial discrimination.

If the first case lacks any fact deemed material in the second case, or contains any material facts not found in the second, then it is not precedent, but only persuasive argument.

The law then is reduced, in the case of the judge, to the art of drawing distinctions, and in the case of the lawyer, to the art of anticipating the distinctions the judge is likely to draw.

Based on my own judicial experience that goes back to 1961, I suggest that 90 percent of the cases appearing before a court of general trial jurisdiction or general appellate jurisdiction fall within two categories: where the law and its application alike are certain, or where the law is certain and the only question concerns its application to the facts before it.

What may be considered by a lawyer as an “easy” case may be a jaw-breaking one to a student only one-third of the way through a course. Whether the case be “hard” or “easy,” the Pound/Jones formulation is the best test to measure a good decision: not in terms of the correctness or incorrectness of the courts’ application of precedents, and not in terms of the result, for this may simply be congruent with one’s personal philosophy or inclination, but in terms of (1) how thoughtfully and disinterestedly the court weighed the conflicting interests involved in the case and (2) how fair and durable its adjustment of the interest-conflict promises to be. The first goes to the “reasonableness” of the court’s decision; the second to the logical validity of its reasoning.

The function of reflective thought is to face a situation where there is obscurity, doubt and conflict, and to transform that situation to one that is clear, coherent and harmonious with what has gone before and what may occur again.

Because of the doctrine of stare decisis, however, the solving of problems cannot be done on an ad hoc basis. We must respect the overarching consideration that like cases be decided alike. But the beckoning question is always to decide what is a like case.

We have emphasized that, unlike in mathematics and science, there are few immutable major premises in the law. … But the genius of the common law is that these premises are not fixed in cement. In the popular idiom they are always up for grabs, up for grabs to meet changes in our social, political, philosophical and economic climate.

When invention is active, when industry, commerce and transportation bring about new forms of human relations and when community relations change because of the extension of ethical and moral ideas, the law is able to keep pace with the variety and subtlety of social change. … Old” new law may sometimes give way to “new” new law.

Inductive reasoning does not purport to reach truths; its aim is to produce a result that is more probably true than not. Rules of deductive reasoning go further. Properly applied, they present an argument based on the theory that if the premises are true, the conclusion must be true.

It is by this mental training rather than by the explicit, positive knowledge of its technical rules, that logic gives us the power and habit of thinking clearly. Probably more than any other science, a careful study trains and develops the reasoning powers, not merely the power of thinking consistently, but the power of discovering the truth.

The province and duty of the judicial department is to say what the law is.

Any congressional Act repugnant to the Constitution, the paramount law of the land, is void.

At the time of the adoption of the Constitution, all state legislatures recognized the inferior and subject condition of the black race; accordingly, blacks could not be considered as citizens and capable of suing in federal court at that time.

At the time of the adoption of the constitution, in some states (New Hampshire, Massachusetts, New York, New Jersey and North Carolina) all free-born inhabitants, even though descended from African slaves, possessed the right of franchise of electors on equal terms with other citizens.

Where fundamental rights protect conduct, the laws of many states that make such conduct illegal are unconstitutional.