Civilized people have exchanged some part of their chances of happiness for a measure of security.
Sigmund FreudMen have gained control over the forces of nature to such an extent that with their help they would have no difficulty exterminating one another to the last man. They know this, and hence comes a large part of their current unrest, their unhappiness and their mood of anxiety.
Sigmund FreudIt is no wonder if, under the pressure of these possibilities of suffering, men are accustomed to moderate their claims to happiness - just as the pleasure principle itself, indeed, under the influence of the external world, changed into the more modest reality principle -, if a man thinks himself happy merely to have escaped unhappiness or to have survived his suffering, and if in general the task of avoiding suffering pushes that of obtaining pleasure into the background.
Sigmund FreudLet us consider the polarity of love and hate.... Now, clinical observation shows not only that love is with unexpected regularityaccompanied by hate (ambivalence), and not only that in human relationships hate is frequently a forerunner of love, but also that in many circumstances hate changes into love and love into hate.
Sigmund Freud