Naked Capitalism has the post Randy Wray: Taxes and the Public Purpose.

If Congress ever got hold of its senses (no, I’m not holding my breath), it would increase spending (or reduce taxes) to employ idle resources. At some point (probably later rather than sooner) we could come up against resource constraints. At that point we might need to curtail spending and/or raise taxes.

We can examine how to deal with the happy problem of chock-full employment later—we haven’t seen it in the US since WWII and it isn’t on any horizon at present.

Taxes can serve other purposes, too, as I’ve argued earlier in this series. We can use taxes to discourage “sins”—in which case the purpose of the tax is to eliminate “sin” so the optimal sizing of the tax would eliminate sin and hence raise no revenue at all.

Previously, I argued that we can view excessive riches as a sort of “sin” that we want to tax away. Some commentators have argued that high tax rates on high incomes in the early postwar period “worked” by discouraging corporations from paying high incomes to top executives. Exactly! That is how sin taxes are supposed to work. The goal is not to raise revenue but to reduce sin.

This is the clearest description of the attitude MMT proponents have about taxes.  It doesn’t cover all taxes, though.  The topic will garner more attention in later articles.  Above, I have excerpted some statements on issues on which I am particularly focused.  There is more good stuff in the article.