Individualists have always been accused by their enemies of being "atomistic" -- of postulating that each individual lives in a kind of vacuum, thinking and choosing without relation to anyone else in society. This, however, is an authoritarian straw man; few, if any, individualists have ever been "atomists." On the contrary, it is evident that individuals always learn from each other, cooperate and interact with each other; and that this, too, is required for man's survival. But the point is that each individual makes the final choice of which influences to adopt and which to reject, or of which to adopt first and which afterwards. The libertarian welcomes the process of voluntary exchange and cooperation between freely acting individuals; what he abhors is the use of violence to cripple such voluntary cooperation and force someone to choose and act in ways different from what his own mind dictates.
Murray Rothbard, The Libertarian Manifesto
[rothbard]
A common defense of the State holds that man is a "social animal," that he must live in society, and that individualists and libertarians believe in the existence of "atomistic individuals" uninfluenced by and unrelated to their fellow men. But no libertarians have ever held individuals to be isolated atoms; on the contrary, all libertarians have recognized the necessity and the enormous advantages of living in society, and of participating in the social division of labor. The great non sequitur committed by defenders of the State, including classical Aristotelian and Thomist philosophers, is to leap from the necessity of society to the necessity of the State.
Murray Rothbard, "The Moral Status of Relations to the State," The Ethics of Liberty
[rothbard]
Libertarians are generally what might be called simplistic and "vulgar" individualists.
[...] While only individuals exist individuals do not exist as isolated and hermetically sealed atoms. Statists traditionally charge libertarians and individualists with being "atomistic individualists," and the charge, one hopes, has always been incorrect and misconceived. Individuals may be the only reality, but they influence each other, past and present, and all individuals grow up in a common culture and language. (This does not imply that they may not, as adults, rebel and challenge and exchange that culture for another.)
[...] It is almost embarrassingly banal to emphasize that point, but apparently many libertarians aggressively overlook the obvious.
Murray Rothbard, "The Nationalities Question"
[rothbard]
Liberty as I have defined it does not preclude as guidance for one's acts any form or degree of advice and influence, if voluntarily accepted, which, originates elsewhere than within himself. This guidance might be religious influences, evidence from historical records, scientific knowledge, the advice of another person, or even processes of mental telepathy or clairvoyance or insight from mystical origins, to whatever extent these may occur. If willingly accepted, the act resulting from such influences is as much an act of liberty as would be any other.
So liberty as I have defined it is not limited to self-willed conduct arising from total isolation. All these other forces can operate to influence one's acts as a free man. I would even argue that such influences operate at their best and their fullest only under liberty.
F.A. "Baldy" Harper, in an address given before the Mont Pelerin Society at St. Moritz, Switzerland, on September 4, 1957
[harper]