incalculable future and for other children of men. Compensation for us, who suffer grievously from life, he does not promise. On the way to this distant goal your religious doctrines will have to be discarded, no matter whether the first attempts fail, or whether the first substitute-formations prove to be unstable. You know why; in the long run nothing can withstand reason and experience, and the contradiction religion offers to both is only too palpable. Not even the purified religious ideas can escape this fate, so long as they still try to preserve anything of the consolation of religion. Certainly if you confine yourself to the belief in a higher spiritual being, whose qualities are indefinable and whose intentions cannot be discerned, then you are proof against the interference of science, but then you will also relinquish the interest of men. Footnote 4: The twin gods Αόγος-Ἀνάγκη of the Dutchman _Multatuli_. And secondly: note the difference between your attitude to illusions and mine. You have to defend the religious illusion with all your might; if it were discredited—and to be sure it is sufficiently menaced—then your world would collapse, there would be nothing left for you but to despair of everything, of culture and of the future of mankind. From this bondage I am, we are, free. Since we are prepared to renounce a good part of our infantile wishes, we can bear it if some of our expectations prove to be illusions. Education freed from the burden of religious doctrines will not perhaps effect much alteration in man’s psychological nature; our god Αόγος is not perhaps a very powerful one; he may only fulfil a small part of what his forerunners have promised. If we have to acknowledge this, we shall do so with resignation. We shall not thereby lose our interest in the world and in life, for we have in one respect a sure support which you lack. We believe that it is possible for scientific work to discover something about the reality of the world through which we can increase our power and according to which we can regulate our life. If this belief is an illusion, then we are in the same position as you, but science has shown us by numerous and significant successes that it is no illusion. Science has many open, and still more secret, enemies among those who cannot forgive it for having weakened religious belief and for threatening to overthrow it. People reproach it for the small amount it has taught us and the incomparably greater amount it has left in the dark. But then they forget how young it is, how difficult its beginnings, and how infinitesimally small the space of time since the human intellect has been strong enough for the tasks it sets it. Do we not all do wrong in that the periods of time which we make the basis of our judgements are of too short duration? We should take an example from the geologist. People complain of the unreliability of science, that she