On 1/18/15, our regular foursome discussed a particularly tough book, The Concept of Nature (1920). We chose this one over his more famous Process and Reality (1929) based on Owen Flanagan's recommendation that this older work was more accessible.
And part of it is. The first couple of chapters clearly set out Whitehead's approach, which is to dodge both metaphysics (talking about the world-in-itself or about how minds create it a la the post-Kantian framework that dominated the philosophic landscape) and phenomenalism, i.e. talking about the apparent world as opposed to the world science investigates. These to Whitehead are one and the same, and though he doesn't address such obvious issues in light of such a view as perceptual illusions until right near the end of the book (in a chapter called "Summary" that's actually a separate lecture from the rest of the series; I'd advise reading the first two chapters then skipping straight to that), he gives a nice scolding to those that would deny experience by insisting on, e.g. Aristotle's view of substance or Locke's distinction between primary and secondary qualities.
But if he's going to say that molecules and atoms, and space-time as used in scientific work are not the hidden reality behind experience, but instead are part of experience, abstracted from it, then he has to lay out how this "abstraction" works, and that's what most of the book becomes, creating a system of 4-dimensional geometry that eventually lets us talk about all of what science talks about but which starts with the phenomenological insight that the world of our experience of a duration. If this sounds like Bergson to you (Bergson wrote about 20 years earlier), you're right; he credits Bergson in the text. And if (as we did) you were confused given Bergson's fundamental insight what exactly we were supposed to then DO with that philosophically, Whitehead gives you an answer.
We should note that the presentation of Whitehead's system of relative space-time, motion, and objects is supposed to be his non-mathematical presentation of a version laden with actual proofs in An Enquiry Concerning the Principles of Natural Knowledge. Nonetheless, the chapters about the system itself are a hard slog, with definitions building on definitions, and it's hard to get excited about the effort given that apparently it was not particularly influential (though not totally forgotten), unlike Whitehead's previous edifice, Principia Mathematica (which we described some of the findings from in a previous episode). From what I've read, Einstein himself was aware of Whitehead's alternate interpretation of General Relativity (which the system outlined in this book is supposed to provide, though we, including our resident physicist Dylan, really couldn't put the whole story together well enough to have any opinion of its plausibility) and didn't buy it.
For other connections to PEL episodes beyond Bergson and Russell, try our episodes on Husserl (who was working at the same time as Whitehead and came to similar conclusions independently), Merleau-Ponty (who was influenced by both Husserl and Whitehead and had his own take on the primacy of perception over scientific abstraction), Deleuze (who was very influenced by both Bergson and Whitehead, though you'll hear more about this in our Not School discussion on Deleuze than in the PEL episode), and the granddaddy of all process philosophy, Heraclitus.
One more note: I've not tried to give a summary of Whitehead's whole argument here, as I just did that on the the precog (the transcript of which is available for Citizens). In this case, as with Jaspers, I wrote the precog after we did the group discussion, so it's likely more cogent, and certainly more organized, than anything you'll hear us say as a group. That's the current status of precogs now: Though we'd wanted to do these in advance for all episodes to help orient our discussions, we weren't able to get them done consistently, and they only get downloaded about half as much as a normal episode, so it didn't seem worth it. However, we've had a few episodes since deciding to stop where we felt that we didn't give a very organized introduction to the text, such that most of the audience would likely be confused about what the reading was actually about. In this discussion, I was one sentence into the overview when we started debating Whitehead's relation to Kant and Faraday. So in cases like that, if I or one of the other guys has the energy, we'll try to record a precog after the fact (to post before the episode gets edited) to help orient listeners. You can take a listen to these last two precogs and let us know how you like this approach!