There are only two ways by which to obtain values from other people: either by trade, or by plunder. Only one is moral.
Voluntary exchange is moral and just. Legalized theft, facilitated by government via taxation and crony capitalism (often under the guise of “justice”) is immoral and unjust. We are either free people or we are not. Capitalism, or more exactly, “free enterprise” is the economics of free people. As Professor Williams explains: