1. The fundamental principle of anarchism is nonviolence. This is hardly unusual – most values systems call violent actions – murder, rape, abuse, kidnapping, thievery – immoral. Violence is doing something to another person or their property without their consent. A person’s property is what they’ve created or modified to make more useful, or what they’ve received in trade (including money or goods in exchange for labor or services) or as a gift.
2. You can determine whether an action is consensual or not by what happens when you refuse to do it. If you are punished for refusing, that action is not consensual.
3. Government exists because of taxes. Without taxes, there would be no government.
4. Taxes are nonconsensual. If you refuse to pay taxes, you’ll be punished by being imprisoned.
5. Government is necessarily a violent institution. When people consensually give their money in exchange for goods and services, that’s called a business. Therefore, if you believe that violent actions are immoral, then government is innately immoral. For many people, this is the end of the conversation and all they need to know to become anarchists. However, there are also many major practical advantages to an anarchist society.
6. Violent institutions have serious innate disadvantages, because they did not earn their resources (money, land and natural resources, people’s lives), and are therefore able to expend those resources in ways that are not profitable, leading to decisions that are at best injudicious, frequently corrupt, and often destructive. This includes war – when was the last time you saw a war that didn’t involve a government?
7. To compound the problem, because violent institutions obtain their resources nonconsensually, they have a monopoly over their population, and don’t have to earn those resources by providing quality goods and services to that population.
8. All the goods and services that government offers, could be provided by businesses. Yes, including roads. (See Walter Block’s book The Privatization of Roads and Highways for a great deal more on that subject.) This is why a common refrain you’ll hear from anarcho-capitalists is, “Privatize it!” It’s infinitely preferable for goods and services to be provided privately rather than by government, because it’s consensual, the success of the business is dependent on the quality and desirability of the goods or service it offers, there’s economic motivation for competition instead of monopoly, and the business has to earn its money and therefore will fail if it expends its resources towards nonproductive ends.
9. In an anarchy, many economic forms could exist side by side. I could be a capitalist while my neighbors are communists, socialists, syndicalists, agorists, etc. Think of how communes can exist even within our government-enforced, currency-monopolized capitalist system. As long as no one’s forcing anyone into anything (free association), in an anarchy any and all economic systems could exist that people find it advantageous to participate in. This is why you’ll find anarcho-capitalists, anarcho-communists, etc. – people who agree on the principle of anarchism, but would choose to live in rather different ways within an anarchy.
For me, anarchism is the only non-hypocritical stance to take for someone who claims to value nonviolence.