A man can reason, come to conclusions, and take actions on the basis of those conclusions. In the freedom of nature, man is not prevented from taking action on the basis of his understanding, though that action may not succeed. The foundation of non-aggression as a principle lies in the nature of freedom. Freedom, in the human context, is freedom from interference by other humans. Each man stands at the center of his own honeycomb cell, with his freedom to act delimited by the walls where his freedom to act comes up against that same freedom exerted by others.
Freedom requires freedom of thought and freedom of action.
One without the other is useless. A corollary of freedom of thought and action is the freedom to keep the products of united thought and action - property, in whatever form, tangible or intangible. Ultimately, one must recognize that an aggressor due to his act owes a debt of recompense to the defender - which may be measured in money or in other units. This is because justice in the case of physical damage to the defender, deprivation of the use of property, or any other demonstrable harm requires that the aggressor restore the defender to the state the defender enjoyed before the aggressive act. In the realistic context of imperfect knowledge or in the presence of non-rational individuals, there may be situations in which one individual initiates the use of force on another without intent.