Men are not rational beings, as commonly supposed. A man is a bundle of instincts, feelings, sentiments, which severally seek their gratification, and those which are in power get hold of reason and use it to their own ends, and exclude all other sentiments and feelings from power.

Man is not a rational animal; he is a rationalizing animal.

Man is many things, but he is not rational.

I wonder who it was defined man as a rational animal. It was the most premature definition ever given. Man is many things, but he is not rational.

Man cannot make principles, he can only discover them.

Man is a rational animal. So at least we have been told. Throughout a long life I have searched diligently for evidence in favor of this statement. So far, I have not had the good fortune to come across it.

Me pregunto quién definió al hombre como animal racional. Fue la definición más prematura que se ha dado nunca. El hombre es muchas cosas, pero no racional.

a man only knows what he's experienced

A man may imagine things that are false, but he can only understand things that are true.

It is only by the exercise of reason that man can discover God. Take away that reason, and he would be incapable of understanding anything; and, in this case, it would be just as consistent to read even the book called the Bible to a horse as to a man. How, then, is it that those people pretend to reject reason?

Men are reasoning rather than reasonable animals.

the current situation being a toss-up as to what you want to believe. Man is not a rational animal, he is a rationalizing animal. Hence you will find that often what you believe is what you want to believe, rather than being the result of careful thinking.

The reasonable man adapts himself to the world around him; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.

No rational argument will have a rational effect on a man who does not want to adopt a rational attitude.