While the author is a very engaging communicator, to my mind he hasn't actually written a true introductory book for those with little or no prior knowledge of physical chemistry here. Like all too many writers of "introductory" books, what he's written is more of a re-introductory booklet for those already familiar with the field and its jargon, who simply want to go back and re-visit the fundamental concepts of the field in a more romanticized and philosophical way.
But even at that, the writer is apt to confuse you, for he starts using terminologies well before he's even defined them and before you even know that any explanation of those terms is forthcoming. And so, in the interim, if you don't just give up on the book, you're muddling through, completely confused and feeling quite bad about your intelligence.
Atkins' explanations of Gibbs free energy, entropy, and enthalpy, despite his efforts to speak plain English, are about as confusing as any I've ever read on the subject. I'm giving this book three stars only because I feel like his heart's perhaps in the right place, but if I didn't suspect that, I'd give it two.