Many libertarians define their libertarian philosophy in terms of the nonaggression principle. However, in the writings in which the nonaggression principle is advocated, a simple fact is invariably overlooked: No one has succeeded in producing a definition of aggression that is not derived from the specific social outcome they desire.

If a person desires a society with robust intellectual property laws (both patent and copyright laws), then they will define aggression in such a way that violation of patent and copyright laws constitutes aggression. If a person desires a society with copyright laws but not patent laws, then they will define aggression in such a way that violation of a copyright law constitutes aggression on the one hand, while the attempt to enact and enforce a patent law constitutes aggression on the other hand. Finally, if a person desires a society with no intellectual property laws, then they will define aggression in such a way that the attempt to enact and enforce any intellectual property laws constitutes aggression. One can see this principle at work if one reads the libertarian literature on intellectual property over the last fifty years.

One of the most important insights in subjectivist social thought comes from Benedict de Spinoza in his book The Ethics:

It is thus plain from what has been said, that in no case do we strive for, wish for, long for, or desire anything, because we deem it to be good, but on the other hand we deem a thing to be good, because we strive for it, wish for it, long for it, or desire it.(2008, p.56)

A version of the same theoretical insight appears in Mises’s Epistemological Problems of Economics (1976, p.151). Mises refers to a “dictum of Jacobi” as quoted by Bohm-Bawerk:

We originally want or desire an object not because it is agreeable or good, but we call it agreeable or good because we want or desire it; and we do this because our sensuous or supersensuous nature so requires. There is, thus, no basis for recognizing what is good and worth wishing for outside of the faculty of desiring—i.e., the original desire and wish themselves.

These important insights applied to the nonaggression principle mean that we will seek a concrete social arrangement not because it is nonaggressive, but rather we will call “nonaggressive” that social arrangement that we seek. When we seek something, that thing is good or agreeable to us because it is in our nature to experience as “good” or “agreeable” that which we seek. When we seek a specific social arrangement, institution, or outcome, we simply use a different terminology to indicate our pleasure and agreement. Instead of calling it “good” we call it “nonaggressive.”

The problem with the nonaggression principle is the same as that with natural law. As Mises writes in Theory and History:

It is useless to emphasize that nature is the ultimate arbiter of what is right and what is wrong. Nature does not clearly reveal its plans and intentions to man. Thus, the appeal to natural law does not settle the dispute. It merely substitutes dissent concerning the interpretation of natural law for dissenting judgments of value. (1985, p. 49)

Similarly, we add little to our knowledge in stating that libertarianism is based on nonaggression. In doing so, we merely substitute disagreement on what constitutes aggression for disagreement on the kind of society we each desire.