A desire presupposes the possibility of action to achieve it; action presupposes a goal which is worth achieving.
Ayn Rand

A language presupposes that all the individual users possess the organs.
Ferdinand de Saussure

Active creation is conceived as a transitive action in which there is always presupposed an object about which the agent is concerned; it is virtually but not formally transitive because it makes, not presupposes, an object.
William Ames

Every orientation presupposes a disorientation.
Hans Magnus Enzensberger

Gaiety is a quality of ordinary men. Genius always presupposes some disorder in the machine.
Denis Diderot

Light is meaningful only in relation to darkness, and truth presupposes error. It is these mingled opposites which people our life, which make it pungent, intoxicating. We only exist in terms of this conflict, in the zone where black and white clash.
Louis Aragon

The attainment of the economic aims of man presupposes peace.
Ludwig von Mises

The planet's survival has become so uncertain that any effort, any thought that presupposes an assured future amounts to a mad gamble.
Elias Canetti

This is the task, I think, of a letter movement. But it should be set up only in states where a significant response can be achieved, for a letter movement necessarily presupposes a strong organization.
Fredrik Bajer

Unionization, as opposed to communism, presupposes the relation of employment; it is based upon the wage system and it recognizes fully and unreservedly the institution of private property and the right to investment profit.
John L. Lewis