Religion is an illusion and it derives its strength from the fact that it falls in with our instinctual desires.

No, our science is no illusion. But an illusion it would be to suppose that what science cannot give us we can get elsewhere.

We believe that it is possible for scientific work to gain some knowledge about the reality of the world, by means of which we can increase out power and in accordance with which we can arrange our life. If this belief is an illusion, then we are in the same position as you. But science has given us evidence by its numerous and important successes that it is no illusion.

We are naturally grieved over the fact that a just God and a kindly providence do not guard us better against such influences in our most defenseless age. We thereby gladly forget that as a matter of fact everything in our life is accident from our very origin through the meeting of spermatozoa and ovum, accident, which nevertheless participates in the lawfulness and fatalities of nature, and lacks only the connection to our wishes and illusions.