Review – Homo Deus

June 8, 2017

The End of Strife:

The four horsemen of the Apocalypse are Famine, Plague, War and Death – pop culture does not always get this right – and after defeating the first three we might now just continue and conquer Death, too, and see, where this leads us as a species. Homo Deus starts with a rather bold claim: throughout history, famine, plague and war were the central topics of human life, and recently, all three of them have been made all but irrelevant.

For all of history, humans have lived a couple bad days away from starvation, a couple bad rats away from the pocks and a couple bad words away from an all-out war against their neighbours. There are still starving people in the world, but no longer because there is not enough food for them, but because letting them starve furthers someone’s agenda. We talked about his before. There are still infectious diseases in the world, but they remain local outbreaks, and we no longer perceive them as a force of nature, but rather as a consequence of our own lack of hygiene and prevention. And there are still combats fought in the world, but they are no longer considered a standard option in foreign politics.

So instead of seeing famine, plague and war as given facts of life, we as a global society have recognized the human element behind these three banes and have worked with all our might to yield us from them – with very good success. The arising question is: now that our former central points of life are no longer concerning us, what are we going to do with our time instead? According to Homo Deus, we could (and some of us already do) strive for immortality, bliss and divinity.

Immortality – in a limited sense – has historically been achieved by performing superhuman deeds. We still know who Aristotle, Michelangelo and Albert Einstein are, but they are not around anymore. Future technology may make immortality a physical reality, either by preserving the body through medicine and therapy, or the mind by transfer into a non-decaying host. Or maybe not. Human bliss has been a very recent addition to the list of government issues. Without real external hardships to overcome, can we finally try and be happy? Should we as a society make this one of our goals? The titular Homo deus then would have powers that can only be described as divine. Humanity could have the power to alter their body or mind, to live on other planets or maybe in the internet, and to collect and process more data than anybody would have ever thought possible.

Strikingly, Harari does not necessarily propose immortality, bliss and divinity as worthy or wise human efforts, he just states that these are the directions that rich and famous “thought leaders” have already taken, for the better or worse.


Being Human:

What is a human? A major part of the book is dedicated to the definition of a human as an ontologic concept. While this sounds like an easy task, philosophers from Plato to Kant have struggled with this. In many religions, humans are thought to have a unique characteristic, a soul, that sets them apart from all other beings. Harari on the other hand argues that the human body has evolved naturally to adapt to different environments, and the human mind has evolved naturally to process data on threats and opportunities to ensure survival and procreation. But what would be the evolutionary advantage of a soul, the human spark, as Harari calls it? How would it be connected to our natural bodies, and for what biological purpose? I know scientists that are also devout christians or muslims, without finding a contradiction in their beliefs, so make of that what you want.

Now, what is a human? The most distinctly human traits may be cooperation on an otherwise unheard of and enormously flexible scale, and the invention of narratives to find meaning. It is a narrative that coloured paper should be exchangeable for food and labour. It was also narratives that created national borders, the stock market and social networks. And when the spirits of hunter-gatherer societies and the gods of ancient and modern times became inadequate to explain modern society, humans just invented humanism to dignify and give meaning to the human existence. And now, all that is changing again and technology is usurp the role of the protagonist in our stories.


Technology out of control:

Modern biology offers a mechanistic view of the human, exposes even our most sacred emotions of love and hate as simple heuristic learning algorithms, evolved over millions of years to help us make quick decisions. However, if we are just organic data processors, is there still a meaningful division between humans, animals and algorithms? Neuroscience tells us that even our most “rational” decisions are just the result of autonomous processes in our brain. How can we have free will when it all boils down to chemicals and currents in our heads that can be altered from the inside and from the outside at any moment. An interesting thought: if there was a drug that makes you desire cheese, would that chemical will be different from your other desires? If you then act on your desire and eat some cheese, are you exerting free will?

With the concept of free will standing disputed, other research indicates the the notion of a consistent “self” may be grossly exaggerated. In fact we have a neuronal committee changing our personality and experience to react to different situations, only to spin everything into a consistent self-narrative after the fact. So who are we, and what exactly makes us “us”? Putting the final nail in the coffin of humanity’s sense of self-worth, computers just got better than humans in intellectual work, threatening a new industrial revolution to everybody whose job includes any kind of data processing. So, with our image as consistent, meaningful, dignified individuals crumpling and artificial intelligence on the rise, what could the future look like?

Harari offers three perspectives, each one unpleasant in it’s own way. We already mentioned how algorithms are now getting better than humans at driving, data entry and analysis, even music creation. The next decade of development might make millions of people completely irrelevant to economic and societal progress. This includes not only office workers, but artists, doctors, lawyers and scientists, as algorithms are already entering their fields. Will this be the onset of a freedom never experienced before, or bring about problems never experienced before?

But maybe humans stay somewhat relevant, after all, by giving up free will. Big Data analysis already allows frustratingly accurate predictions of individual human behavior based on their tweets and facebook posts, so why not just give up and hand over all control to machines altogether? If this sounds unwise, have a look at your phone: there’s a good chance you already have it tell you how to exercise, work and sleep more efficiently by analysing your heartbeat, skin pressure and other cues that humans just cannot process. Why not just accept that algorithms will soon know more about us than we do ourselves and let them give meaning to our reality?

Or maybe humans stay relevant and self-determined, but the definition of humans gets stretched a bit. Remember the beginning of this review, where rich guys throw lots of money at discovering ways to defeat death? What if they succeed? What if the future offers the possibility to improve the human body and mind in ways that seemed inconceivable just a few years ago? Imagine rich guys getting their laziness genes removed by gene therapy, getting implants that alter electric currents in their brain, to make them more creative. Maybe throw in some robot limbs, just for good measure. Technological progress could create a gap in the global society that no longer merely divides rich and poor people, but people and superhumans (the titular Homo deus). This is the stuff of science fiction movies.

But maybe nothing like that ever happens? Homo Deus is big on self-defeating prophecies: if some researcher ever discovers, how the economy truly and unambiguously works, companies would use that knowledge to their advantage, thus changing the system. The global worker’s revolution did not happen, but that does not mean Marx was wrong. Because enough capitalists saw the truths of his prediction, the working conditions became just humane enough to suppress any revolts. And maybe, as an increasing number of people gets aware of the more frightening technological innovations, at some point we as a society just decide to stop and do something else. Just because this has never happened before does not mean it will never happen.


What can we learn from Homo Deus?

In summary, the author presents three clear and distinct trains of thought: the past and present human agenda, the attempt of a definition of “human”, and the possible implications of technological progress. These overarching themes are interconnected at several points and branching of into side topics, and sometimes the author simply has to many balls in the air, to my taste. Homo Deus lacks stringency, sometimes dropping a topic to follow an aside, only to drop that and continue the first one two chapters later. At no point does this get too confusing to follow, but I often wished that the ideas be presented in a different order. This may be entirely due to my personal taste, though.

More severely, while the author’s reasoning is sound and clear overall, sometimes it breaks apart on a detail level. For example, Harari argues that “the system” fosters the constant “fear of missing out” people have nowadays, because your boss wants you to constantly check your emails. In fact, your boss wants you to stop checking your stupid emails every five damn minutes and finally do the job you’re paid for. Similar contradictions show up in the historical role of religions or recent developments of neuroscience.

I don’t think this dissolves Harari’s theories, but keep in mind that here is an author who states in this very book that creating narratives is probably of humanity’s greatest strength and weakness, then goes on to spin history, philosophical and scientific anthropology, computer science and neurobiology into one giant, consistent human story. At least Homo Deus provides a good narrative, so does it matter when some details don’t fit?

Significant parts of the book are dedicated to disparaging religions, and, no matter how you personally think about the topic, a lot of it is a bit stupid. The dumbest argument I found was that Zeus “obviously” does not hurt when you destroy his temple. Worshipping Zeus may be slightly out of fashion today, but his devout followers would just counter that “obviously” Zeus actually does hurt, too. No matter what your religious preferences are, this part of Homo Deus just does not bring anything new to the table.

Also, most of what is said in the book has been said before. Terry Pratchett coined Pan narrans”, the storytelling chimpanzee, as a better-fitting name for us than Homo sapiens. The advent of new disruptive technology has been analyzed more than once (here is an example). But still, Homo Deus offers not only a good summary of previous ideas but also a very interesting philosophical perspective.

Should I read Homo Deus?

Harari is neither a technophobic scaremonger nor a wide-eyed tech evangelist. He just shines some light on the philosophical implications of current technological trends. Homo Deus is not a prophetic glimpse into the future nor a manual of things humankind should do and avoid. It is just a chronicle of historic developments and recent advances of both technology and the role of humans in the world. And it’s pretty good at that! I am not a historian or philosopher, so Homo Deus offered me a very unusual view on technological progress, which I found profoundly interesting, and it made me think about how I attribute value and meaning to things.

So if you want some food for thought about circumstances and consequences when we humans lose control of our technology, and the possibility that this may already have happened does not scare you, this is for you.



To conclude, I’d like to give you the three closing questions of Homo Deus to roll around in your head:


  1. Are organisms really just algorithms, and is life really just data processing?
  2. What is more valuable – intelligence or consciousness?
  3. What will happen when non-conscious but highly intelligent algorithms know us better than we know ourselves?


Key points:

  • Ancient challenges for humanity are suddenly not a problem anymore.
  • Humans may not be the unique and precious snowflakes that we think we are.
  • It is unexpectedly hard to explain the difference between human, animal and algorithm
  • While machines are getting better at everything, how will humans still be relevant in the future?

Author affiliations:

Yuval Noah Harari is a professor of history at Hebrew University, Jerusalem. His research interests include large-scale developments of the human condition, and the relationship between biology, philosophy and history. He has written other books on these topics and runs his own website.


Review copy:

copy bought
Random House, September 1, 2016
ISBN-10: 1910701882
ISBN-13: 978-1910701881


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Homo Deus - A Brief History of Tomorrow Book Cover Homo Deus - A Brief History of Tomorrow
Yuval Noah Harari
Random House
September 1, 2016
Homo Deus: Eine Geschichte von Morgen
philosophical, matter-of-fact, sometimes preaching

Are humans more important than algorithms? Is there a uniquely human trait? What can we do, after solving all old problems? Homo Deus has a proposal for us.

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