“Natural science is either the description of forms (morphology) or the explanation of changes (etiology). Neither can afford us the information we chiefly desire.”

“Science is not a taxi-cab that we can get in and out of whenever we like.”

“Philosophy ... is a science, and as such has no articles of faith; accordingly, in it nothing can be assumed as existing except what is either positively given empirically, or demonstrated through indubitable conclusions.”

“The conviction that the world, and therefore man too, is something which really ought not to exist is in fact calculated to instil in us indulgence towards one another: for what can be expected of beings placed in such a situation as we are? From this point of view one might indeed consider that the appropriate form of address between man and man ought to be, not monsieur, sir, but fellow sufferer, compagnon de misères. However strange this may sound it corresponds to the nature of the case, makes us see other men in a true light and reminds us of what are the most necessary of all things: tolerance, patience, forbearance and charity, which each of us needs and which each of us therefore owes.”

“A book can never be anything more than the impress of its author's thoughts; and the value of these will lie either in the matter about which he has thought, or in the form which his thoughts take, in other words, what it is that he has thought about it.”

“Thus the will to live everywhere preys upon itself, and in different forms is its own nourishment, till finally the human race, because it subdues all the others, regards nature as a manufactory for its own use. Yet even the human race...reveals in itself with most terrible distinctness this conflict, this variance of the will with itself; and we find homo homini lupus.”

“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.”