It is the courage to make a clean breast of it in the face of every question that makes the philosopher.

There are three stages in the revelation of truth. The first is to be ridiculed, the second is to be resisted and the third is to be considered self-evident.

Animals learn death first at the moment of death;...man approaches death with the knowledge it is closer every hour, and this creates a feeling of uncertainty over his life, even for him who forgets in the business of life that annihilation is awaiting him. It is for this reason chiefly that we have philosophy and religion.

Anyone can squash a bug but all professors of this world couldn't build one.

Sexual passion is the cause of war and the end of peace, the basis of what is serious... and consequently the concentration of all desire

The vanity of existence is revealed in the whole form existence assumes: in the infiniteness of time and space contrasted with the finiteness of the individual in both; in the fleeting present as the sole form in which actuality exists; in the contingency and relativity of all things; in continual becoming without being; in continual desire without satisfaction; in the continual frustration of striving of which life consists. . . Time is that by virtue of which everything becomes nothingness in our hands and loses all real value.

Man is the only animal who causes pain to others with no other object than wanting to do so.