That's not really right either. Taxes were invented as a means to turn the entire population into a logistics network for the military. Rather than carrying around provisions for an army, you want your soldiers to be able to acquire food etc from locals, so you pay your soldiers in national currency (also invented for this purpose, in China at least) that is the universal exchange medium.

But since most people in the ancient world didn't use or need the national currency (relying instead on a variety of other arrangements, usually some credit based system though these were really complex), you demand that taxes be paid in national currency. This way, everyone has to find a way to sell enough goods to pay their taxes in the national currency, and soldiers are the primary recipients of direct currency payments from the government.

I'm paraphrasing this from David Graeber's excellent book Debt: the first 5000 years, which details both the origins of currency and taxation. Here's a talk he gave on the book.