I came across a section from “Book V” of The Gay Science, which was added to the second edition in 1887 (apologizes for its length):
In science, convictions have no rights of citizenship, as is said with good reason. Only when they decide to descend to the modesty of a hypothesis, of a provisional experimental point of view, of a regulative fiction, may they be granted admission and even a certain value within the realm of knowledge—though always with a restriction that they remain under police supervision, under the police of mistrust.
But does this not mean, more precisely considered, that a conviction may obtain admission to science only when it ceases to be a conviction? Would not the discipline of the scientific spirit begin with this, no longer to permit oneself any convictions? Probably that is how it is.
But one must still ask whether it is not the case that, in order that this discipline could begin, a conviction must have been there already, and even such a commanding and unconditional one that it sacrificed other convictions for its own sake. It is clear that science too rests on faith; there is no science “without presuppositions.” The question whether truth is needed must not only have been affirmed in advance, but affirmed to the extent that the principle, the faith, the conviction is expressed: “nothing is needed more than truth, and in relation to it everything else has only second-rate value.”
This unconditional will to truth: what is it?
What do you know in advance of the character of existence, to be able to decide whether the greater advantage is on the side of the unconditionally mistrustful or of the unconditionally trusting? Yet if both are required, much trust and mistrust: whence might science then take its unconditional faith, its conviction, on which it rests, that truth is more important than anything else, even than any other conviction?
Just this conviction could not have come into being if both truth and untruth showed themselves to be continually useful, as is the case. Thus, though there undeniably exists a faith in science, it cannot owe its origin to such a utilitarian calculus but it must rather have originated in spite of the fact that the inutility and dangerousness of the “will to truth,” of “truth at any price,” are proved to it continually.
Consequently, “will to truth” does not mean “I will not let myself be deceived” but—there is no choice—“I will not deceive, not even myself”: and with this we are on the ground of morality. For one should ask oneself carefully: “Why don’t you want to deceive?” especially if it should appear—and it certainly does appear—that life depends on appearance; I mean, on error, simulation, deception, self-deception; and when life has, as a matter of fact, always shown itself to be on the side of the most unscrupulous polytropoi.
Such an intent, charitably interpreted, could perhaps be quixotism, a little enthusiastic impudence; but it could also be something worse, namely, a destructive principle, hostile to life. “Will to truth”—that might be concealed will to death.
Thus the question “Why science?” leads back to the moral problem, “For what end any morality at all” if life, nature, and history are “not moral”? … But one will have gathered what I am driving at, namely, that it always remains a metaphysical faith upon which our faith in science rests—that even we devotees of knowledge today, we godless ones and anti-metaphysicians, still take our fire too from the flame which the faith thousands of years old has kindled: that Christian faith, which was also Plato’s faith, that God is truth, that truth is divine.
I’ve become increasingly interested in fringe realities: viewpoints made up of concepts that are dubious or even demonstrably false, and yet that still might as well be true. For example, consider the phenomenon (again, not caring whether it’s true or not) described by many observers of jungle cats: they eat a psychotropic plant—which, depending on which article you read, either heightens or blurs their senses—before hunting. Now, many might argue that imbibing a substance with any chance of lessening one’s ability to catch prey and ultimately survive is a silly—or suicidal—gambit, but notice that it need not matter; jaguars seem to hunt just fine, high or sober.
Scientific tests may one day uncover the specific effects of the drug (and all the different senses that cats have that humans can’t comprehend yet)—but what good would that do, either to the cats or to the people observing them? Who knows, the cats may even be eating the substance in spite of a hindering of hunting prowess, but no matter: enough cats hunt successfully enough to perpetuate the species, down through a long-enough chain to allow natural selection to act.
I’m not sure if Nietzsche is getting to something similar here: that is, that we should be asking questions about our selves, not about an external ideal of our selves—let alone about how to force every other self to fit into the mold of the ideal. Such unnecessary hoop-jumping (or, trying to squeeze a square peg into a round hole, as the saying goes), was the a priori problem of Plato, who started with the premise that there must be, somewhere—in the ether, or in another unworldly realm—a universal essence of each thing, and that each individual was thus a deviation from said universal essence, in other words a crude copy of a perfect original. How sad (and dangerous) of a philosophy is that?
Note, however, that Nietzsche still sits on the side of team science (writing “we godless ones…”), while simply cautioning proponents of rational inquiry that perhaps even rational inquiry deserves, well… rational inquiry. Ultimately, learning about something is an effort to control it, and that tendency deserves sharp critique on a continual basis. But the scientific method does have its purpose; it would be much worse not to employ it all, than to occasionally let it get carried away.