The evils of the body are murder, theft, and adultery; of the tongue, lying, slander, abuse and idle talk; of the mind, covetousness, hatred and error.
The cure of the part should not be attempted without treatment of the whole. No attempt should be made to cure the body without the soul. Let no one persuade you to cure the head until he has first given you his soul to be cured, for this is the great error of our day, that physicians first separate the soul from the body.
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.
Concepts which have proved useful for ordering things easily assume so great an authority over us, that we forget their terrestrial origin and accept them as unalterable facts. They then become labeled as 'conceptual necessities,' etc. The road of scientific progress is frequently blocked for long periods by such errors.
The fossil record implies trial and error, an inability to anticipate the future, features inconsistent with an efficient Great Designer (although not with a Designer of a more remote and indirect temperament)
Another error is an impatience of doubt and haste to assertion without due and mature suspension of judgment. For the two ways of contemplation are not unlike the two ways of action commonly spoken of by the ancients; the one plain and smooth in the beginning, and in the end impassable; the other rough and troublesome in the entrance, but after a while fair and even. So it is in contemplation; if a man will begin with certainties, he shall end in doubts; but if he will be content to begin with doubts, he shall end in certainties.
To free a man from error is to give, not to take away. Knowledge that a thing is false is a truth. Error always does harm; sooner or later it will bring mischief to the man who harbors it.
There is an error common to both oligarchies and to democracies: in the latter the demagogues, when the multitude are above the law, are always cutting the city in two by quarrels with the rich, whereas they should always profess to be maintaining their cause; just as in oligarchies the oligarchs should profess to maintain the cause of the people, . .