It seems, from these passages, that individuality—what distinguishes one man from another—is connected with the body and the irrational soul, while the rational soul or mind is divine and impersonal. One man likes oysters, and another likes pineapples; this distinguishes between them. But when they think about the multiplication table, provided they think correctly, there is no difference between them. The irrational separates us, the rational unites us. Thus the immortality of mind or reason is not a personal immortality of separate men, but a share in God’s immortality.

Bertrand Russell, History of Western Philosop…, loc. 762