Man’s search for meaning, by Victor Frankl

We who lived in the concentration camps can remember the men who walked through the huts comforting others, giving away their last piece of bread. They may have been few in number, but they offer sufficient proof that everything can be taken from a man but one thing: the last of the human freedoms — to choose one’s attitude in any given set of circumstances, to choose one’s own way.

[…]

Man is not fully conditioned and determined but rather determines himself whether he gives in to conditions or stands up to them. In other words, man is ultimately self-determining. Man does not simply exist but always decides what his existence will be, what he will become in the next moment. By the same token, every human being has the freedom to change at any instant. Therefore, we can predict his future only within the large framework of a statistical survey referring to a whole group; the individual personality, however, remains essentially unpredictable.

If you haven’t already: Read. This. Now.