It is a mistake to believe that science consists in nothing but conclusively proved propositions, and it is unjust to demand that it should. It is a demand made by those who feel a craving for authority in some form to replace the religious catechism by something else, even a scientific one.
Sigmund FreudPsycho-analysis has taught us that a boy's earliest choice of objects for his love is incestuous and that those objects are forbidden ones - his mother and his sister. We have learnt, too, the manner in which, as he grows up, he liberates himself from this incestuous attraction. A neurotic, on the other hand, invariably exhibits some degree of psychical infantilism. He has either failed to get free from the psychosexual conditions that prevailed in his childhood or he has returned to them - two possibilities which may be summed up as developmental inhibition and regression.
Sigmund FreudReligion is an attempt to get control over the sensory world, in which we are placed, by means of the wish-world, which we have developed inside us as a result of biological and psychological necessities... If one attempts to assign to religion its place in man's evolution, it seems not so much to be a lasting acquisition, as a parallel to the neurosis which the civilized individual must pass through on his way from childhood to maturity.
Sigmund Freud