If there is a single principle by which I live – it is:

“No one may threaten or commit violence (“aggress”) against another man’s person or property. Violence may be employed only against the man who commits such violence; that is, only defensively against the aggressive violence of another…Most Libertarians and even Conservatives are familiar with the rule and even defend it; the problem is not so much in arriving at the rule as in fearlessly and consistently pursuing its numerous and often astounding implications. “

Murray Rothbard- from the essay War,Peace, and The State in his book: Egalitarianism as a Revolt Against Nature, and Other Essays

“Today is already the tomorrow which the bad economist yesterday urged us to ignore. The long-run consequences of some economic policies may become evident in a few months. Others may not become evident for several years. Still others may not become evident for decades. But in every case those long-run consequences are con- tained in the policy as surely as the hen was in the egg, the flower in the seed.

From this aspect, therefore, the whole of economics can be reduced to a single lesson, and that lesson can be reduced to a single sentence. The art of economics consists in looking not merely at the immediate hut at the longer effects of any act or policy; it consists in tracing the consequences of that policy not merely for one group but for all groups.”

Henry Hazlitt – Economics In One Lesson