In [chess], where the pieces have different and "bizarre" motions, with various and variable values, what is only complex, is mistaken (a not unusual error) for what is profound
Extemporaneous speaking should be practised [sic] and cultivated. It is the lawyer's avenue to the public. However able and faithful he may be in other respects, people are slow to bring him business if he cannot make a speech. And yet there is not a more fatal error to young lawyers than relying too much on speech-making. If any one, upon his rare powers of speaking, shall claim an exemption from the drudgery of the law, his case is a failure in advance.
There is nothing grand or noble in having the use of a slave, in so far as he is a slave; or in issuing commands about necessary things. But it is an error to suppose that every sort of rule is despotic like that of a master over slaves, for there is as great a difference between the rule over freemen and the rule over slaves as there is between slavery by nature and freedom by nature . .
Delusions, errors and lies are like huge, gaudy vessels, the rafters of which are rotten and worm-eaten, and those who embark in them are fated to be shipwrecked.
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.
The majority of mankind would seem to be beguiled into error by pleasure, which, not being really a good, yet seems to be so. So that they indiscriminately choose as good whatsoever gives them pleasure, while they avoid all pain alike as evil.
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.
Every limited mind demands a certain freedom of expression, and the man who cannot express himself satisfactorily without the stimulation derived from the spirited mode of two centuries ago should certainly be permitted to follow without undue restraint a practice so harmless, so free from essential error, and so sanctioned by precedent, as that of employing in his poetical compositions the smooth and inoffensive allowable rhyme.
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.
What is toleration? It is the prerogative of humanity. We are all steeped in weaknesses and errors: Let us forgive one another's follies, it is the first law of nature.