On occasion I read a blog or something that tries to explain why the author is not a libertarian/voluntaryist. They normally all break down the same way.
The main objection always seems to be that they have a perceived problem or a lifeboat scenario that they can come up with to try and justify the need for a coercive monopoly on force rather than a voluntary interaction between two parties. The causes change, the stories change, but the final conclusion is always the same, they believe it points out a need for governmental aggression.
The problem is that what one person considers a pressing problem is different from what another person considers a pressing issue, and the issues are never clear cut. The methods always have negative side effects, and the benefits of government force are rarely as great as promised. For instance let's say that I determine that a road needs to be built between town A and town B and that this justifies me taking the land in-between by force to accommodate my new road. I will also need tax money to pay for the new road. This is a pretty simple example and one based on real events that occur all of the time, not just some made up lifeboat setup. Still it is one that the majority of people probably believe justifies the use of force.
Let's think about this for a second. First let's say I am right and that road would be a boon for society and would make everyone in these towns much happier wealthier and wiser. If the consensus is 100% in the area that the road would be a great thing, then I should have no problem buying the land from the current owners as they know that the road will improve the value of their remaining land that abuts against the new road. If they are unwilling to sell then there really isn't a consensus that the new road is such a good idea. Also it is unlikely that there would be universal agreement that the path I laid out for the new road is the best path for the road to take, maybe my path bypasses a town that really wants the new road to pass by them. Then let's say that I am going to demand a tax of $1000 per person that lives in towns A and B because they are the ones who will benefit from this new road. Then I have detractors who say that the road could be built for half the amount I am looking to spend. I have other detractors who say that even if the average benefit to town A and B is going to be the dollar equivalent of $1000 per person that the benefit is not equally distributed and that a few people will benefit by many thousands of dollars while other benefit very little and so an equal tax on everybody to pay for my road is really a wealth transfer from the many to the few. Suddenly the justification for the use of force to build my road is much less clear, and the most moral solution is to build my road from private funds put up by those who stand to profit the most from it and to create a path where I have the cooperation of the land holders along that path. Does this mean that my road will be perfectly straight? Maybe not, but because it was built and funded through voluntary means will ensure that it does not create a huge controversy in the community about the cost, the path, who benefits, and where the road should go. Voluntary action creates harmony, force creates disharmony. Does that mean everyone will be happy with the end result? No, but those who are unhappy with it probably were not the people who put up their land and money to see the road created so they can complain, but they really have very little say in the situation and if they had really wanted more say they could have put up their own money and land before the road was built. In the current paradigm of government force, everyone thinks they have an equal say because everyone was forced to pay for these kinds of projects.