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.

Analogies, it is true, decide nothing, but they can make one feel more at home.

Taboo restrictions are distinct from religious or moral prohibitions. They are not based upon any divine ordinance, but may be said to impose themselves on their own account. They differ from moral prohibitions in that they fall into no system that declares quite generally that certain abstinences must be observed and gives reasons for that necessity.

We are never so defensless against suffering as when we love.

It is unreasonable to expect science to produce a system of ethics-ethics are a kind of highway code for traffic among mankind-and the fact that in physics atoms which were yesterday assumed to be square are now assumed to be round is exploited with unjustified tendentiousness by all who are hungry for faith; so long as physics extends our dominion over nature, these changes ought to be a matter of complete indifference to you.

The aim of psychoanalysis is to relieve people of their neurotic unhappiness so that they can be normally unhappy.

It is a predisposition of human nature to consider an unpleasant idea untrue, and then it is easy to find arguments against it.