Idea: Reductionism is incompatible with one form of generalism, but not the other.
Reductionists believe reality is at the bottom. You don’t really exist. You are just your parts, behaving and interacting in the various ways they do.
In contrast, generalists think reality is at the top. But there are two versions of this belief.
One version says wholes are primary. A part is just its larger whole, behaving and developing in a particular way. This is “unificationism.” The larger and more inclusive something is, the realer it is.
The other version says origins are primary. Derivatives and descendants only exist because of the originals they come from. This is “originalism.” The more original something is, the realer it is.
Reductionism vs. Unificationism
Reductionists and unificationists agree about one thing: you don’t really exist. While we talk about you, the best, most scientific, most realistic account of things would never mention you. Everything you are and do would be better described in terms of smaller (more basic), or larger (more inclusive) things behaving in certain ways. You’re just a manifestation of those lower or higher (more real) things.
However, you can’t be both a reductionist and a unificationist. You can’t say both that parts are primary and that wholes are primary. But people try. They are reductionists about physics and genetics while also believing that what really matters is the race, the species, the environment, the cosmos, etc.
Reductionism vs. Originalism
In contrast, you can be both a reductionist and an originalist. I think Richard Dawkins is a good example: what’s really real about you is your genes (you’re just a “survival machine” for them), which are quasi-Platonic, eternal forms.
Does this mean that originalists agree that you don’t really exist? Not really. A child may seem to have less weight and oomph in reality than his parents, but he can still interact, and interfere, with them. Similarly, you may be an image of Plato’s Forms, and thus be less real. But you are perfectly capable of encountering the Forms and of entering their world of ultimate reality (according to Plato).
Originalism vs. Unificationism
Finally, you could be both an originalist and a unificationist. That’s what pantheists like Spinoza are: the whole universe is God, and God is the whole universe. The most inclusive thing is also the most original thing.