We are never so defenseless against suffering as when we love. - Sigmund Freud

Conscience is the internal perception of the rejection of a particular wish operating in us.

Quite often they are lines of thought starting out from more than one centre, but not without their points of contact; almost invariably one train of thought is accompanied by its contradictory opposite, associatively linked to it by contrast.

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.