A new argument against anarcho-capitalism that I’ve come across from a minarchist is as follows: anarcho-capitalism is not a legitimate philosophy because there is not universal consensus on how a stateless society would solve certain problems.
There is plenty wrong with this argument. First of all, I’m not sure there is any philosophy or group that has everyone in lockstep agreement on everything. There is constant debate within the scientific community on various topics. A very well-known example of this is the effects of climate change on humans and the earth. The disagreement does not mean that climatology is wrong, but only that certain members of the community are not correct.
Does there even have to be agreement among anarcho-capitalists? Isn’t the whole point behind libertarianism to use the market to solve problems instead of central planning? The market is where ideas can be freely tested and the best solutions can rise to the top. That cannot occur within the framework of central planning. To claim that a centrally planned solution is superior to all others is to claim to possess perfect knowledge. That is impossible of course.
Since this argument came from a minarchist, there is quite a bit of irony in it. Anarcho-capitalism is apparently incorrect because not everyone agrees on how, for example, regional defenses against foreign invaders might work, but they do agree that the market is the best way to come up with the solution. Minarchists may agree that the state would solve this problem, but they do not necessarily agree on how. Why do minarchists (or any other group) get a pass on that?
Furthermore, while he groups all anarcho-capitalists who “disagree” on certain ideas into one collection, many non-libertarians will not make a distinction between anarcho-capitalists and minarchists. To them they’re all just libertarians—libertarians who cannot even agree whether the state should exist or not! That’s quite a difference in opinion, isn’t it? If the minarchists can use the lack of universal consensus to show that anarcho-capitalism is wrong, why can’t the same be said about libertarianism in general?
This does not necessarily prove that anarcho-capitalism or any other philosophy is correct. It only shows that this argument is not valid.