Let us resurrect this dead horse, if only for a while.

I like the Spinoza quote, but I don’t really understand the first part – “which exists by the necessities of its own nature”. What does that mean? Also, was he talking about metaphysical free will, or was he talking about human freedom and free, independent human beings?

Anyhow, the second part seems understandable. There is nothing that is “determined in its actions by itself alone”, depending on how you look at it. Are the rules that govern the actions of an atom a part of the atom? Do they lie outside of the atom? If yes, then where are the rules? Isn’t the behavior of each subatomic particle (protons, electrons) influenced by all of the others? At the smallest scale, it is clear that there is no freedom.

What about the largest scale – what you are calling “everything”? If we think of everything as a unitary whole, isn’t it true that the actions of the whole are determined by (and a reflection of) the sum of the actions of its parts?

All systems either follow rules or behave chaotically/randomly. Since an object/entity following rules is not exhibiting free will, and since an object/entity behaving chaotically is not exhibiting free will, and since there are no behavioral choices other than following rules or behaving chaotically (or some combination), I conclude that the whole concept of free will is an indefinable abstraction.