The past cannot be affected by what we do, and therefore, if truth is determined by what has happened, it is independent of present or future volitions; it represents, in logical form, the limitations on human power. But if truth, or rather ‘warranted assertability’, depends upon the future, then, in so far as it is in our power to alter the future, it is in our power to alter what should be asserted.

Bertrand Russell, History of Western Philosop…, loc. 2937