I do not in the least underestimate bisexuality... I expect it to provide all further enlightenment.

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

Thinking is an experimental dealing with small quantities of energy, just as a general moves miniature figures over a map before setting his troops in action.

There is little that gives children greater pleasure than when a grown-up lets himself down to their level, renounces his oppressive superiority and plays with them as an equal.

From error to error one discovers the entire truth.

[The child] takes his play very seriously and he expends large amounts of emotion on it. The opposite of play is not what is serious but what is real.

Children are completely egoistic; they feel their needs intensely and strive ruthlessly to satisfy them.