The ego represents what we call reason and sanity, in contrast to the id which contains the passions.

Religious doctrines … are all illusions, they do not admit of proof, and no one can be compelled to consider them as true or to believe in them.

In mourning it is the world which has become poor and empty; in melancholia it is the ego itself.

Conservatism, however, is too often a welcome excuse for lazy minds, loath to adapt themselves to fast changing conditions.

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.

Thinking in pictures is, therefore, only a very incomplete form of becoming conscious. In some way, too, it stands nearer to unconscious processes than does thinking in words, and it is unquestionably older than the latter both ontogenetically and phylogenetically.

Neurosis is the inability to tolerate ambiguity.