As noted, the first two parts of Timothy Ferris' The Mind's Sky: Human Intelligence in a Cosmic Context are very good. In the first he looks at the cosmos, our relationship to it, the drive for communication, how galactic-level cultures might appear and survive, etc., and in the second he looks at the human mind, how the brain functions, and how we are a complex of various types of "intelligences". This latter is very interesting, quoting studies that show that the "conscious mind" acts as something of a "press agent" for the whole, attempting to put a unified and intentional front on actions which are not necessarily volitionally made. Also looking at how different types of intelligence often "compete for space" in the limited real estate of the brain, with several fascinating examples. I really wish he had simply taken these two parts and done a "wrap it all up" last section to the book.
Unfortunately, the third part of the book sounds almost petulant, and has elements that have not "aged well" over the 15 years since this was written. As regular readers of these reviews will recall, I've recently been catching up on my reading from books bought in the early 1990's and there has been a lot of times when I've found the stuff I'm looking at hopelessly dated, especially from a computer basis. That's one aspect here, as is his addressing "political" hot-button issues from 1991 which seem almost quaint at this remove. I don't suppose that one can really fault an author for writing "in time", but it was a rather stark contrast of how good the first two parts of this book are compared to the final section.
Again, the main thrust of this book is fascinating, the concept of intelligence and where it might stand in relation to the universe at large. One very interesting point Ferris makes is that "intelligence", in the way we generally think of it, might not be such an "inevitable" development of life. From a standpoint of something like SETI, this would be defined as the ability to send and receive radio signals, and there were many millions of years of quite extensive life on this planet without that happening, and even over the course of the presence of "modern humans", this ability has only manifested over the past century. The Mind's Sky suggests that "intelligence" is a particular adaptation to planetary environmental stressors, and only made possible on Earth by the impact events which eradicated the dinosaurs and allowed for the spread of various mammals (including those that developed opposable thumbs and fine-control digits for transport through trees), and the Ice Ages which appear to have favored Homo Sapiens over its various "cousins". The question is left on the table about just how frequently does "intelligence" arise ... only on planets with enough chaos to elicit its development, but not so much to eradicate it before it can flourish?
Anyway, this is a worthwhile book to pick up, despite the let-down of the third section. It appears that a "reprint" edition of this is still out there, so might be available at your local brick-and-mortar book vendor, but you can get a "very good" copy of the original hardcover from the Amazon new/used guys for a measly $0.01 (plus $3.99 shipping), which is what I'd suggest were you interested in adding this to your collection!