Homo Deus is Professor Harari's follow-up to the blockbuster (at least by sociology's standards) Sapiens. Instead of "A Brief History of Humankind," this is "A Brief History of Tomorrow," Harari's vision of where our present might lead us, based on our past thus far. His prediction: having done away with plague, famine, and war (more or less), humans will now look to attain immortality, bliss, and divinity. We are not, Harari proves, all that far off from any of these goals.
While life expectancy and general health keep improving, the possible lifespan of a human being has not changed at all. Though few and far between, ancient Egyptians and even Mesopotamians were quite capable of living into their eighties, just as we are now. But simple good health won't be enough anymore, at least not for humanity's ultra-rich elite. Why settle for winkles when you can have smooth skin? Indeed, why settle for any less than perfect body part or organ if you could heal or replace them and remain twenty-five until some unnatural death visits you? We already replace joints and hearts with those of other animals' or artificial copies, it's not such a leap forward for the wealthy to keep replacing parts as long as they can.
Bliss is arguably the easiest attained of these new goals. We're already doing it: drugs. I'm sorry, medication. Our burgeoning knowledge of chemistry and physiology allows us to medicate all sorts of mental ills; even carefully applied electricity can work wonders on the brain's neural activity. Why should anyone be miserable when they can just swallow a little pill and feel good again? Why should we tolerate the occasional accidents caused by tired truck drivers or plane pilots when we can create lasting focus and wakefulness with a cap that sends weak electrical pulses through the brain?
Divinity...this dream is a little less attainable. Omniscience might be a better word to describe what Harari is talking about. The speed with which humanity learns new things seems to be increasing at an exponential rate. In his example of the internet, he reminds us that twenty years ago it was nearly unheard of and poorly understood. Now the whole world runs online, most jobs and people depend on it in some way or another, and many of us are irrevocably attached to it. Similarly with biology, we barely understand our own bodies but our knowledge is growing every single day. For at least an elite class, cursed with extremely long lives and the ability to medicate themselves into any mental state they wish, the realm of knowledge will be the last real playground.
Harari's writing is, as in his first book, highly engaging. He's utterly brilliant, but speaks to the layman with great ease: "If modernity has a motto, it is 'shit happens.'" (pg. 200) His explanation of group dynamics is fascinating, particularly in his descriptions of how democracy works and the delusions people feed themselves to justify suffering in the name of nationalism (pg. 302). Did you know that sick people tend to vote more conservatively? Seriously. It's on page 339.
My one hang up about this book is something Harari says early on but then seems to work off the opposite assumption for the rest of the book. He notes that in the age of steam, at the start of the Industrial Revolution, people thought of the human body and mind in terms of steam, because that was the dominant technology of the day. Hence Freud's theories on pent up sexual frustrations finally boiling to a head at some random moment. Similarly, we talk of our bodies and minds in the language of computers - we act the way our genes program us to, we have different systems that have separate functions but report to the motherboard of our brain. It's the technology du jour, so that's the way we see things. But then Harari goes on for the entire rest of the book to talk about the mind as a set of algorithms, and goes on at great length about this fact plus reminds us of it frequently. Didn't he just say that we shouldn't fall into the trap of describing ourselves in terms of our technology because it's just a metaphor and might not be how things actually work? Or is he saying that this time, we're right and we really are just incredibly complex computers? I wish he would have explained this contradiction more thoroughly. Still, it's another superb read and I recommend anyone interested in the future of humanity (everyone, yes?) to pick it up.