Robert A. Heinlein

History has the relation to truth that theology has to religion -- i.e., none to speak of.

Robert A. Heinlein, in Science and Religion

Never try to out-stubborn a cat.

Robert A. Heinlein, The Notebooks of Lazarus Long, in Success and Failure

Never worry about theory as long as the machinery does what it's supposed to do.

Robert A. Heinlein, in Science and Religion

To be matter of fact about the world is to blunder into fantasy -- and dull fantasy at that, as the real world is strange and wonderful.

Robert A. Heinlein, in Life and Death

Women and cats will do as they please, and men and dogs should relax and get used to the idea.

Robert A. Heinlein, in Men and Women

Yield to temptation -- it may not pass your way again.

Robert A. Heinlein, Time Enough for Love (Lazarus Long), in Vice and Virtue