Explain Like I'm Five

Let's turn the question around. You benefit from the many things other people's taxes have provided, even before you were born. You were probably born in a hospital funded by taxes. The hospital staff was educated by public schools and federally subsidized student loans. You drive on public roads, and are (at least in theory,) protected by publicly funded cops, firefighters, and military. (I did say in theory.) You probably get your electricity, water, sewer and trash pickup from a public utility - even though you pay for your usage, you still benefit from the public expenditure to build and maintain that infrastructure.

So the real question is how is not paying taxes not theft? You'd be a freeloader, stealing from the rest of us.

You opt into it by living in society. If you don't want to pay taxes, find yourself a cave in the woods. If you use the roads to get to work, then you need to pay for the roads. (This applies to all public things, like if you want an educated populace, you need to pay for schools, even if you aren't going to the school yourself. Taxes is a way to pay for all this stuff)

Thousands of years of civilization have taught us that it's more efficient for everyone to pitch in to help each other than it is for everyone to live like a hermit and hoard their wealth.

You're not asking this in good faith.

However, nobody has actually tried to simplify an answer yet.

Taxes are a form of social contract between all taxpaying members of a country.

While it is not truly voluntary, it it also only applied when a person takes part in specific aspects of the social structure. So it can be avoided, just not without eschewing the benefits that come with being part of that country.

By partaking in the aspects of life in a country that incur taxes, you are, indirectly, agreeing to pay them that may or may not be fair. It may or may not give you any feasible alternatives to life in that country, and it decidedly does not leave any pleasant options. But you can avoid taxes, without legal consequences for not paying them, by not engaging in taxable activities.

It would suck for sure.

Now, does that mean taxes aren't theft? Define theft.

If I come to up to you and say "hey jimbob, if you come over here and mow my grass, I'll give you a gallon of milk. But, you gotta give a half pint of that to Gary over there because he gets a cut of all the milk that I give to people since he makes sure the cows stay healthy", is Gary stealing?

Gary is also providing a service. Me and Gary have a mutually beneficial agreement. You do not have to mow my grass. But once the offer is extended, and accepted, trying to say that Gary stole anything from you is not going to be a believable statement.

That's what taxation is. It's an agreement between everyone involved that "Gary", the government, gets a cut of money out of various exchanges of funds. In return, ideally, Gary keeps providing services to everyone.

Again, that's in an ideal world. In reality, not every government actually provides services to the taxed. Often enough, governments make every effort possible to not provide services as expected. But that's not the same thing as taxation itself being theft, it's a given government stealing while using taxes as the method.

So, what choices do you have to avoid taxes?

Well, you'll have to live life without monetary income, since you likely live in a country that taxes that. Difficult, but not impossible. You'll have to avoid owning taxable property. Here in the US, that's usually vehicles, homes/land, and similar real property. That's not actually difficult if you live in the right places, but if you're also not making monetary income, your choices for where to live become very unpleasant if you don't have very good friends and family to rely on.

You'll also likely have to avoid buying most things, since sales taxes exist. That's the really hard one to avoid because most people take part in the social agreement and will not give you goods or services without monetary exchange. Not impossible, but it's going to be a brutal life.

So, the choices absolutely are not fair. Since you also can't go anywhere livable without dealing with taxable transactions, you can't just opt out entirely and go live in the woods away from governments. Everywhere livable is owned by a government somewhere.

But that still doesn't make taxation itself theft, only specific implementations of taxation, and that is a different thing.

There's many folk in Appalachia with no legal identity. Go move out there with the Amish if that's what you want, no id = no taxes.

You are in a contract with the government. Maybe an involuntary one, but still a contract. This contract gives you rights and benefits, but also obligations and responsibilities.

When the government does not uphold their end of the contract, or changes it to essentially only obligations for you and no benefits, then it becomes extortion. Still not exactly theft, but closer to what you mean.

However, the vast majority of people get benefits that far outweight the costs of the contract. Safety, transportation, education, utilities, etc.

How is the definition of theft determined? Typically the definition is determined by the government. Why would the government define its own funding source as theft?

It is 100% there.

It’s legal because of the 16th amendment.

I mean, maybe it is, but so what? The law of the jungle never ended; you can do whatever you want with enough force on your side.

Put another way, we arbitrarily exclude the ruling state from the definition of theft, so we can discuss the extralegal kind better.

Taxation is not theft because you get a functioning society in return (in theory); effectively, you get free time to pursue your interests instead of being forced to scrounge for survival.

Now, the government issuing more currency at will... that reduces the value of the money we all earn at those jobs we work in order to pay the taxes. That is theft.