A central part of Wolffian cosmology was the notion of a possible world – an alternative to the actual world. The notion appears also in Baumgarten's cosmology, but the nature of these worlds is necessarily quite different. In Wolff, it seems that these worlds are meant to be individual entities, although not actual – they are thoughts flying in God's mind, but infinitely detailed and thus completely determinate. With Baumgarten, on the other hand, there are no non-actual individuals, thus, merely possible worlds can be nothing but universals.
Indeed, what we are dealing with in Baumgarten's cosmology is more like a notion or concept of world – Baumgarten starts from the actual world and abstracts certain features that belong to the world. One could then add more features to these features of ”world in general” and these combinations might even be non-contradictory and therefore possible – yet, these combinations would still have an extension of at most one individual thing, that is, they would be predicates of actual world or no world at all.
World, for Baumgarten, is then such a series of actual finite entities, which is not a part of any other series. Without further ado, Baumgarten simply accepts that there is such a totality of actual finite entities, although nothing speaks against the possibility that we might have only a series of ever larger collections of finite entities.
World is not just a combination of finite entities, but an ordering of them, for Baumgarten. Indeed, there are several nexuses holding worldly entities together – causal chains and series of ends, for instance. It is then an important part of the very concept of a world that is must have some regularity and coherence – otherwise, it wouldn't even be unified. By this statement, Baumgarten denies that fables or faery tales could form any possible world.
Because world consists of finities, it cannot be completely good, but must contain some badness or imperfection. In particular, Baumgarten says, world cannot be completely necessary. Thus, Baumgarten can deny Spinoza's theory that world would be necessary. Then again, the existence of the world works also against an acosmicist interpretation of Spinoza – there is something else beyond God.
So much for the general notion of world, next time we shall see what Baumgarten has to say about the elements of the world.