How do we determine what the right course is? Some people will appeal to Utilitarian concerns, what benefits the most people even if some people get hurt. Some people will appeal to justice, where justice simply means that the outcomes match the outcomes they desire.
While in theory, Utilitarian concerns make sense. However, a person's well being is subjective and cannot be compared to others. Because of this, Utilitarian arguments revolve around financial gains and losses. But since our well being is more than just money, such measures are useless.
Justice is a good place to appeal. Without a coherent theory of justice, we may actually be promoting injustice. Justice is just proper action. Policy recommendations based on claims of injustice, such as minimum wage laws or progressive taxation, are based on the claims that income distribution is unjust. This is a incoherent claim. Without an understanding of the purposes of prices or money, claims about injustice in income distribution make no sense.
Before we can determine what is just, we must have a coherent set of principles, a starting place from where we can examine policies. These principles must be based on promoting mutual cooperation and reducing conflict. The must promote civility and not barbarity.
This makes the first principle easy, the non-aggression or non-initiation of force principle. You cannot initiate force against your fellow human being. This principle is generally agreed upon by most people yet hardly anyone actually exercises it. This principle alone will not get us very far unless we have other principles that determine what is an initiation of force.
The next important principle is property. Every system of political thought has a principle of property. Some adhere to a principle that property is collective while others adhere to a theory of private property. Since our goal is to minimize conflict, a system of collective ownership of property cannot work. Collective ownership means there is always conflict for every piece of property that more than one person wants to use at any given point. If we consider a spectrum of ownership from a pure collective to a pure private system of property ownership, there will always be conflict until we reach a system of pure private ownership. The US operates under a mixed system where the government claims ownership over every piece of property and allows private individuals the right to use the property at its please. The US government reserves the right to make decisions about how all property can be used up to and including taking complete ownership of the property. Because of this, there is always conflict between private owners and government over most property.
These two principles alone cannot determine justice. Since a person must have a right to defend himself from threats of force, we need social norms that tell us when an implied threat is sufficient to justify defensive force. For example, if someone raises a fist at you, when can you strike first as a defensive measure? If someone is two feet from you, a defensive first strike is likely justified. If someone is thirty feet from you, it may not be. However, if you are walking down a dark alley and someone is coming up to you in a threatening manner, defensive action may be justified at thirty feet.
Claims of injustice, however, are more clear. The claim that workers are unfairly unpaid and that a minimum wage is justified is baseless. The worker owns his body and has a right to you it to produce labor in exchange for money. The employer presumably acquired his money justly and has a right to give it to the worker. Forcing the employer to give more money to the worker violates property rights. It tells both parties under what terms they may make the exchange. Since the minimum wage is backed by threats of force, this policy violates both the principle of non-aggression and property rights.
The justification for taxes is that people use government services and that these services need to be paid for. As long as the payment for the service is voluntary, there is no problem. As soon as the government forces people to pay for a service, with threats of violence or confiscation of property, then these payments become unjust. That people use the services government provides is not relevant. If government does not require payment for the use of a service, that does not justify theft to pay for the service. Taxes are unjust.