Leibniz and Berkeley both seem to me to be absolutely right in most of their critiques of Locke, taken simply as critiques. Even Berkeley’s bold claim that matter doesn’t exist, if we limit “matter” to what Locke and his contemporaries thought “matter” was, now seems to be basically true. Their alternative systems, however, contain significant crackpot elements. The sheer amount of work “God” has to do in each should have tipped them off that they were cheating.
Looking at the index of Process and Reality, I see that Whitehead makes copious references to Locke and Hume, but only a few to Leibniz and Berkeley — despite the fact that his system seems to bear more resemblance to the latter. In fact, for all Whitehead’s love of Locke, it is difficult for me to discern the relationship between the two. So why the insistence on Locke and Hume? Is it a “political” move, to try to convince his logical positivist friends that he’s working out of the modern tradition? If so, it didn’t work.
Spinoza seems to me to be miles ahead of any of these guys. I’m not ready to sign on and become a Spinozan, but he’s clearly the true radical.