533.
Logical accuracy, transparency, considered as the criterion of truth ("omne illud verum est, quod clare et distincte percipitur."—Descartes): by this means the mechanical hypothesis of the world becomes desirable and credible.
But this is gross confusion: like simplex sigillum veri. Whence comes the knowledge that the real nature of things stands in this relation to our intellect? Could it not be otherwise? Could it not be this, that the hypothesis which gives the intellect the greatest feeling of power and security, is preferred, valued, and marked as true—The intellect sets its freest and strongest faculty and ability as the criterion of what is most valuable, consequently of what is true....
"True"—from the standpoint of sentiment—is that which most provokes sentiment ("I");
from the standpoint of thought—is that which gives thought the greatest sensation of strength;
from the standpoint of touch, sight, and hearing—is that which calls forth the greatest resistance.
Thus it is the highest degrees of activity which awaken belief in regard to the object, in regard to its "reality." The sensations of strength, struggle, and resistance convince the subject that there is something which is being resisted.
534.
The criterion of truth lies in the enhancement of the feeling of power.
535.
According to my way of thinking, "truth" does not necessarily mean the opposite of error, but, in the most fundamental cases, merely the relation of different errors to each other: thus one error might be older, deeper than another, perhaps altogether ineradicable, one without which organic creatures like ourselves could not exist; whereas other errors might not tyrannise over us to that extent as conditions of existence, but when measured according to the standard of those other "tyrants," could even be laid aside and "refuted." Why should an irrefutable assumption necessarily be "true"? This question may exasperate the logicians who limit things according to the limitations they find in themselves: but I have long since declared war with this logician's optimism.
536.