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

It is impossible to escape the impression that people commonly use false standards of measurement — that they seek power, success and wealth for themselves and admire them in others, and that they underestimate what is of true value in life.

In his fight against the powers of the surrounding world his first weapon was magic, the first forerunner of our modern technology. We suppose that this confidence in magic is derived from the over-estimation of the individual’s own intellectual operations, from the belief in the ‘omnipotence of thoughts’, which, incidentally, we come across again in our obsessional neurotics.

Perhaps the hopes I have confessed to are of an illusory nature, too. But I hold fast to one distinction. Apart from the fact that no penalty is imposed for not sharing them, my illusions are not, like religious ones, incapable of correction.

.It is asking a great deal of a man, who has learnt to regulate his everyday affairs in accordance with the rules of experience and with due regard to reality, that he should entrust precisely what affects him most nearly to the care of an authority which claims as its prerogative freedom from all the rules of rational thought.

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.

The view is often defended that sciences should be built up on clear and sharply defined basal concepts. In actual fact no science, not even the most exact, begins with such definitions. The true beginning of scientific activity consists rather in describing phenomena and then in proceeding to group, classify and correlate them.

The interpretation of dreams is the royal road to a knowledge of the unconscious activities of the mind.

When we attempt to imagine death, we perceive ourselves as spectators.