They can do it only by establishing the belief that they are in possession of a power which is higher and stronger—God. Nothing is strong enough: every one is in need of the mediation and the services of priests. They establish themselves as indispensable intercessors. The conditions of their existence are: (1) That people believe in the absolute superiority of their god, in fact believe in their god; (2) that there is no other access, no direct access to god, save through them. The second condition alone gives rise to the concept "heterodoxy"; the first to the concept "disbelievers" (that is to say, he who believes in another god).
141.
A Criticism of the Holy Lie.—That a lie is allowed in pursuit of holy ends 'is a principle which belongs to the theory of all priestcraft, and the object of this inquiry is to discover to what extent it belongs to its practice.
But philosophers, too, whenever they intend taking over the leadership of mankind, with the ulterior motives of priests in their minds, have never failed to arrogate to themselves the right to lie: Plato above all. But the most elaborate of lies is the double lie, developed by the typically Arian philosophers of the Vedanta: two systems, contradicting each other in all their main points, but interchangeable, complementary, and mutually expletory, when educational ends were in question. The lie of the one has to create a condition in which the truth of the other can alone become intelligible....
How far does the holy lie of priests and philosophers go?—The question here is, what hypotheses do they advance in regard to education, and what are the dogmas they are compelled to invent in order to do justice to these hypotheses?
First: they must have power, authority, and absolute credibility on their side.
Secondly: they must have the direction of the whole of Nature, so that everything affecting the individual seems to be determined by their law.
Thirdly: their domain of power must be very extensive, in order that its control may escape the notice of those they subject: they must know the penal code of the life beyond—of the life "after death,"—and, of course, the means whereby the road to blessedness may be discovered. They have to put the notion of a natural course of things out of sight, but as they are intelligent and thoughtful people, they are able to promise a host of effects, which they naturally say are conditioned by prayer or by the strict observance of their law. They can, moreover, prescribe a large number of things which are exceedingly reasonable —only they must not point to experience or empiricism as the source of this wisdom, but to revelation or to the fruits of the "most severe exercises of penance."
The holy lie, therefore, applies principally to the purpose of an action (the natural purpose, reason, is made to vanish: a moral purpose, the observance of some law, a service to God, seems to be the purpose): to the consequence of an action (the natural consequence is interpreted as something supernatural, and, in order to be on surer ground, other incontrollable and supernatural consequences are foretold).
In this way the concepts good and evil are created, and seem quite divorced from the natural concepts: "useful," "harmful," "life-promoting," "life-retarding,"—indeed, inasmuch as another life is imagined, the former concepts may even be antagonistic to Nature's concepts of good and evil. In this way, the proverbial concept "conscience" is created: an inner voice, which, though it makes itself heard in regard to every action, does not measure the worth of that action according to its results, but according to its conformity or non-conformity to the "law."