453. The causes of error lie just as much in the _good_ as in the _bad will_ of man:--in an incalculable number of cases he conceals reality from himself, he falsifies it, so that he may not suffer from his good or bad will. God, for instance, is considered the shaper of man's destiny; he interprets his little lot as though everything were intentionally sent to him for the salvation of his soul,--this act of ignorance in "philology," which to a more subtle intellect would seem unclean and false, is done, in the majority of cases, with perfect _good faith._ Goodwill, "noble feelings," and "lofty states of the soul" are just as underhand and deceptive in the means they use as are the passions love, hatred, and revenge, which morality has repudiated and declared to be egotistic. Errors are what mankind has had to pay for most dearly: and taking them all in all, the errors which have resulted from goodwill are those which have wrought the most harm. The illusion which makes people happy is more harmful than the illusion which is immediately followed by evil results: the latter increases keenness and mistrust, and purifies, the understanding; the former merely narcoticises.... Fine feelings and noble impulses ought, speaking physiologically, to be classified with the narcotics: their abuse is followed by precisely the same results as the abuse of any other opiate--_weak nerves_. 454. Error is the most expensive luxury that man can indulge in: and if the error happen to be a physiological one, it is fatal to life. What has mankind paid for most dearly hitherto? For its "truths ": for every one of these were errors _in physiologicis>_.... 455. Psychological _confusions_: the _desire for belief_ is confounded with the "will to truth" (for instance, in Carlyle). But the _desire for disbelief_ has also been confounded with the "will to truth" (a need of ridding one's self of a belief for a hundred reasons: in order to carry one's point against certain "believers"). _What is it that inspires Sceptics?_ The hatred of dogmatists--or a need of repose, weariness as in Pyrrho's case. The _advantages_ which were expected to come from truth, were the advantages resulting from a belief in _it_: for, in itself, truth could have been thoroughly painful, harmful, and even fatal. Likewise truth was combated only on account of the advantages which a victory over it would provide--for instance, emancipation from the yoke of the ruling powers. The method of truth was _not_ based upon motives of truthfulness, but upon _motives of power, upon the desire to be superior._ _How is_ truth _proved_? By means of the feeling of increased power,--by means of utility,--by means of indispensability,--_in short, by means of its advantages_ (that is to say, hypotheses concerning what truth should be like in order that it may be embraced by us). But this involves _prejudice_: it is a sign that _truth_ does not enter the question at all....