Zarathustra was the first to consider the fight of good and evil the very wheel in the machinery of things: the transposition of morality into the metaphysical realm, as a force, cause, and end in itself, is his work. [...] Zarathustra created this most calamitous error, morality; consequently, he must also be the first to recognize it.
Indeed the reasoned criticism of a prevailing belief is a service to the proponents of that belief; if they are incapable of defending it, they are well advised to abandon it. This self-questioning and error-correcting aspect of the scientific method is its most striking property.
Those who assert that the mathematical sciences say nothing of the beautiful or the good are in error. For these sciences say and prove a great deal about them; if they do not expressly mention them, but prove attributes which are their results or definitions, it is not true that they tell us nothing about them. The chief forms of beauty are order and symmetry and definiteness, which the mathematical sciences demonstrate in a special degree.
He soon felt that the fulfillment of his desires gave him only one grain of the mountain of happiness he had expected. This fulfillment showed him the eternal error men make in imagining that their happiness depends on the realization of their desires.
He who gives himself to a lover because he is a good man, and in the hope that he will be improved by his company, shows himself to be virtuous, even though the object of his affection turn out to be a villain, and to have no virtue; and if he is deceived he has committed a noble error. For he has proved that for his part he will do anything for anybody with a view to virtue and improvement, than which there can be nothing nobler.
More investment sins are probably committed by otherwise quite intelligent people because of "tax considerations" than from any other cause. One of my friends-a noted West Coast philosopher-maintains that a majority of life's errors are caused by forgetting what one is really trying to do. This is certainly the case when an emotionally supercharged element like taxes enters the picture (I have another friend-a noted East Coast philosopher who says it isn't the lack of representation he minds-it's the taxation).
I believe that I have really found the relationship between gravitation and electricity, assuming that the Miller experiments are based on a fundamental error. Otherwise, the whole relativity theory collapses like a house of cards.
The fatal errors of life are not due to man's being unreasonable: an unreasonable moment may be one's finest moment. They are due to man's being logical.
There is no more evil thing in this world than race prejudice, none at all. [...] It justifies and holds together more baseness, cruelty, and abomination than any other sort of error in the world.