Hatred of humanity and love of animals make a very bad combination.

More than any other product of human scientific culture scientific knowledge is the collective property of all mankind.

In nature we find not only that which is expedient, but also everything which is not so inexpedient as to endanger the existence of the species.

The appeal of the cat lies in the very fact that she has formed no close bond with [man], that she has the uncompromising independence of a tiger or a leopard while she is hunting in his stables and barns: that she still remains mysterious and remote when she is rubbing herself gently against the legs of her mistress or purring contentedly in front of the fire.

A man sufficiently gifted with humor is in small danger of succumbing to flattering delusions about himself, because he cannot help perceiving what a pompous ass he would become if he did.

We had better dispense with the personification of evil, because it leads, all too easily, to the most dangerous kind of war: religious war.

Barking dogs may occasionally bite, but laughing men hardly ever shoot!