Many people hold the following view about property: if you acquire something without coercion or deception, then you own that thing. I shall show that this is a serious mistake about property rights. And this mistake leads to a further mistake about taxes.
Lost Objects
My starting point will be a passage in Deuteronomy.
If you see your fellow's ox or sheep gone astray, do not ignore it; you must take it back to your fellow. If your fellow does not live near you or you do not know who he is, you shall bring it home and it shall remain with you until your fellow claims it; then you shall give it back to him. You shall do the same with his ass; you shall do the same with his garment; and so too shall you do with anything that your fellow loses and you find; you must not remain indifferent. (Deut. 22.1-3. see also Ex. 23:4-5)
One can take this passage to be making the oft-repeated, yet oft-neglected Biblical point that merely minding one's own business -- hurting no one and helping no one -- is not enough. People are morally required to go out of their way for others, even when doing so is burdensome and risky. Charity is not morally optional. By focusing on lost animals, the passage emphasizes the great lengths to which the finder must go in order to return lost objects. The finder must return wandering animals to the loser; a non-trivial task without horse-trailers or pickups to pull them! Alternatively, the finder must keep wandering animals, feed them, and shelter them until the loser returns, which might be months or years!
But the rabbis of the Talmud used this lost object passage differently. They made it a jumping-off point for a sustained Talmudic discussion on property rights rather than benevolence. (Bava Metzia 21A-33B).
Some contemporary slogans conflate possession with ownership. "Finders keepers; losers weepers," sing the children. "Possession is nine tenths of the law," say those who possess what they do not deserve. However, the passage emphasizes that what Joe owns is very different than what he has in his possession. When Joe loses an object, it remains his, even if someone else picks it up and takes it home. An object ceases to belong to Joe when he relinquishes his claim on it (by selling or giving it away); not when it falls out of his pocket.
Ownership is a function of choice; it has nothing to do with possession. So keeping a found object (when one could return it) is not just being unhelpful; it is violating the property rights of the loser. It is theft.
Now the rabbis of the Talmud lived in the real world. They realized that all sorts of problems would arise unless the finder eventually becomes the owner. But some people never relinquish their claims. A statute of limitations would solve this problem.
But the rabbis offered a better solution. They stipulated that when a reasonable person would give up hope of recovering a lost object, the object becomes the property of the finder. Even if the loser has not given up hope, the property is no longer his or hers if a reasonable person would have given up hope. Thus, choice -- not possession -- remains the essence of property rights. It is the hypothetical choice of a reasonable person rather than actual choice of an unreasonable loser, but it is still choice.
Broken Contracts
Consider a possibly parallel case. You sign a contract stipulating that you will pay Jane $5.00 on Monday, but you don't pay her. On Tuesday Jane demands, "Give me my money." Is she confused? Or does the $5.00 in your pocket actually belong to her?
One way of thinking is that although you broke the contract, the money is still yours. If Jane goes to court to force you to surrender the money, it is theft. But this is a counterintuitive way to think about the situation. This way of thinking would make sense if property rights depended upon possession, but not if they depend upon choice.
A better analysis of the situation is this. By making the contract, you chose to relinquish ownership of the money on Monday. Since ownership is a function of choice, Jane is right about the money. The $5.00 belongs to Jane. Even though it is in your pocket -- even if you earned it without force or fraud -- the $5.00 does not belong to you. If Jane goes to court to force you to surrender $5.00 to her, it is not theft. Instead, it is uniting money with its rightful owner.
Taxes
Some people say that when you pay taxes -- income tax, sales tax, property tax, etc. -- you are giving your money to the government. Many resent this; some even consider it illegitimate. But this is a mistake.
One common way of thinking about political obligation is this: By living in a democracy, you have explicitly or implicitly agreed to abide by its laws (assuming the laws are not horribly unjust). In particular, you have agreed to abide by the tax laws. So not paying taxes is just like not paying Jane. You have already made the choice to relinquish ownership of a certain amount of money at a certain time. When that time comes, the money is, therefore, no longer yours. When you pay the tax, you are not giving the government your money; you are giving the government its money.
Why does all this matter? The main reason is resentment. Many people resent this or that aspect of the tax code, but some people resent all taxes. They rail against taxes, in general. Now if the government was taking your money, resentment of taxes would make sense. But since the government is taking its money, resentment is inappropriate.
I started with a passage about losing valuable objects, but some things are better lost than kept. Lose the anti-tax attitude; the IRS is just making sure that you honor your commitments.