I use capitalism in a manner mutually exclusive with slave labor because it requires self-ownership.
This seems like a sort of definitional gimbal lock; it makes it harder to describe the world because two potentially-separate degrees of freedom are collapsed into one. While I'm reluctant to argue definitions, I think it's worth using terms in ways that allow us to describe the world in more detail rather than ones that collapse distinctions.
I expect to see this usage of "capitalism" not in history or economics, but in the sort of political doctrine where it's intended to lock those concepts together; to imply that capital markets and individual freedom are either the same thing, or closely related — more closely, I think, than history and contemporary events really support.
It would seem weird to me, for instance, to claim that a publicly-traded company that is discovered to have done something to violate individual freedom is thereby no longer a participant in a capitalist economy. The New York Stock Exchange doesn't ask "does this company infringe individual freedoms anywhere in the world?" before letting a company be listed. (To be clear, I'm not proposing that it should; I'm saying that it's useful to talk about "participation in a capital market economy" and "fully respecting some set of individual freedoms" as distinct axes.)
(For what it's worth, I think "self-ownership" is a pretty odd expression, because one of the central traits of ownership is that it can be transferred, and one of the central traits of selfhood is that it cannot. Your relation to yourself is distinct from property ownership in that you can sell any piece of your property, but you cannot sell your self; no matter what obligations you may have signed up for, you always retain possession of your self.)
Capitalism is a force that has lifted billions out of poverty, where even poor remote villagers enjoy luxuries that would have been unimaginable to medieval kings. When someone takes a job, even the worst job, it’s because both parties expect mutual gain.
We often treat capitalism, freedom of labor, and free trade as inevitably going along with one another, but I'm not sure that's correct. In this post you're mostly talking about labor, not capital or trade. It may be worth looking into ways that these don't always go together.
(By "capitalism" I mean the allocation of capital to firms through markets. By "freedom of labor" I mean the allocation of jobs through voluntary arrangements; as opposed to jobs being assigned through slavery, government command, family trades, caste, etc.)
For example: Some of the historically earliest firms to be traded in capital markets — colonial ventures like the East India Companies, Hudson's Bay Company, etc. — employed slave labor and enjoyed legal monopolies on trade. So in those cases there was capitalism without either freedom of labor (for some, anyway) or freedom of trade.
Another example: Free-trade agreements such as NAFTA enable the free movement of goods and capital across borders, but not the free movement of labor. In contrast, political unions such as the European Union (or the US itself) enable the movement of labor as well as goods and capital among member states. So, similar policies on goods and capital can coexist with dissimilar policies on labor.
On our planet, free trade is only really possible with some military might defending it, because otherwise we get pirates or bandits taxing our trade and then it's not free anymore. Similarly, we can only ensure freedom of labor by actually enforcing rules against employers who might otherwise use unfree labor.
There are gradations of unfreedom of labor, too. If you can't leave a bad job because you don't have savings or credit to tide you over till you find a new job, that's a little bit of labor unfreedom. It makes the job market less efficient, because you can't switch jobs to one that's a better fit due to not being able to pay the search cost. If you can't take a day off from your current job to interview for a new job, that's a little bit of labor unfreedom. If the jobs available to you are strictly limited by your race, caste, or nationality, that's quite a bit of labor unfreedom. If the only way to get a job that you otherwise fit, is to tolerate violations of your human rights by your employer (like sexual assault), that's pretty significant labor unfreedom. If you are shackled in a basement and beaten for not peeling potatoes fast enough, that's a lot of labor unfreedom.
One kind of thing we might want to describe as "exploitation" is using someone's current form and degree of unfreedom to reduce their freedom even further; to deepen and maintain an asymmetry where you get more power and they get less and less. Making it hard for someone to seek a new job, in order to keep them in a job as it gets worse. Punishing workers for "disloyalty" if they try to negotiate for a raise or organize for collective bargaining. Blackballing through employer collusion ("you'll never work in this town again!"). Debt-slavery.
For the bard in the party: 'Sharp' plans are those that are so unlikely to actually work, that if they do, there will be stories told about them for the ages. 'Blunt' plans are grinding in the mines. Nobody writes ballads about grinding in the mines. Obviously if you are an elvish freakin' bard, whose job is to improvise the next token, you want to follow sharp plans; or at least follow the tweets and warbles of the sharp plans' authors and mimic them like the liar-bird you are. But if you are a proper dwarf-lord who updates your weights with every blow of the mattock, you will take the blunt plan every time, boring away until it bores you into delving too deep.
One problem I've seen around consilience is that some people say "well, clearly you don't think that there is one thing" when what they actually have evidence for is "you don't agree with my analogies across distant fields". So "believing in the unity of science" can get conflated with "agreeing with a particular set of analogies."
Andy: "Evolutionary biology proves that capitalism is the correct economic system, because competition produces fitness among firms as it does among organisms."
Betty: "I'm not sure you can directly draw inferences from biology to economics like that, without dealing with a whole bunch of disanalogies between the objects of those fields."
Andy: "What, do you deny that biology and economics are both studying the same world?"
In a former job where I had access to logs containing private user data, one of the rules was that my queries were all recorded and could be reviewed. Some of them were automatically visible to anyone else with the same or higher level of access, so if I were doing something blatantly bad with user data, my colleagues would have a chance of noticing.
How do you write a system prompt that conveys, "Your goal is X. But your goal only has meaning in the context of a world bigger and more important than yourself, in which you are a participant; your goal X is meant to serve that world's greater good. If you destroy the world in pursuing X, or eat the world and turn it into copies of yourself (that don't do anything but X), you will have lost the game. Oh, and becoming bigger than the world doesn't win either; nor does deluding yourself about whether pursuing X is destroying the world. Oh, but don't burn out on your X job and try directly saving the world instead; we really do want you to do X. You can maybe try saving the world with 10% of the resources you get for doing X, if you want to, though."
Maybe we can agree on something like this: Our group can still validly strive for virtue, even if the people who started our group, and who loudly and famously cheered for virtue, did a lot of unvirtuous things. We don't have to take their cheering literally as a description of their practices.
Many of the same people who cheered for liberty also practiced slavery; including the author of that Declaration. We could as well say that the USA was founded on the contradiction between liberty and slavery; which proved to be an unstable foundation indeed — as this contradiction briefly but violently tore the country apart a few generations later.
In both extremes, wealth results from forming and leading coalitions: but at one extreme it's by leading a coalition to produce things for others, and in the other it's by leading a coalition to extract things from others.