As mentioned recently, I am working on a response to Yuval Harari’s book Homo Deus. The reason is because it argues for a dystopian future constructed from a series of fallacious premises. These premises have issues due to the arguments he constructs for them, often through the use of strawmen and ignoring evidence to the contrary or other perspectives. Throughout, it seems that he’s furthering some kind of agenda, and for those who are not familiar with the author, it remains unclear what this involves until about the final third of the book. Having been aware of Harari’s affiliation with the World Economic Forum,1 I began this book suspicious of his motivations for writing it. Within pages, I was inspired to write a response essay because there are far better solutions to the issues he outlines throughout than the ones he proposes.
One of the central premises of Homo Deus is this idea that organisms are algorithms. In chapter 2, on page 96, he introduces the reader to the claim by heading a new section with this very idea. He begins the topic by asking whether we can be sure that animals actually have “a subjective world of needs, sensations, and emotions,”2 fearing that we may be anthropomorphizing their behaviours. On the next page, he clarifies that they do because “all mammals evolved emotional abilities and needs.”3 Moreover, emotions are useful because they are “biochemical algorithms that are vital for the survival and reproduction of all mammals.”4 He then explains what an algorithm is without catching the blatant category error he commits.
An algorithm is just a series of steps for achieving some outcome. The example he appeals to is the same kind that I myself have been using for years now: a culinary recipe. While his example discusses vegetable soup, mine has always revolved around bread because it’s a far more finicky food to make. Ingredients must be introduced in the correct order in specific proportions, and temperature matters a great deal. Anyway, a recipe, in any form it exists, whether on a cue card or on a blog, always consists of the steps required to achieve the desired outcome. But you know what a recipe also requires? A set of hands to take physical ingredients and work with them to make a physical product. The recipe itself is not the same as the loaf of bread when it comes out of the oven. It’s a description of the steps one must take to make bread in the physical world. I can’t eat a recipe. If there was an attempt to eat a recipe, I would be eating the cue card it’s written on. On the next page, Harari actually mentions this in passing, and it’s amazing he doesn’t catch his mistake. Arguably, he will not because he’s [allegedly] not interested in telling the truth, but in furthering a narrative. Anyway, he states “A recipe by itself cannot make soup. You need a person to read the recipe and follow the prescribed set of steps.”5 He does try to save the argument later by stating “humans are algorithms that produce … copies of themselves.”6 That “the algorithms controlling humans work through sensations, emotions, and thoughts.”7 An organism’s body is a calculator, and that what we think of as emotions and sensations are actually algorithms. These calculations are felt as sensations.
There are no calculations occurring in living beings, at least not in the literal sense. Physiological processes can be described as algorithms or calculations, but they are inherently very different. The sensation of hunger is not inherently a series of steps, it’s the presence of the hormone ghrelin in the bloodstream. The brain detects the presence of this hormone and organizes an individual’s behaviour in response. Though we can articulate the release of hormones and neurotransmitters in algorithmic terms, there is no algorithm until a human creates it through observation and representation. Just as you need a person to read a recipe, you need one to write an algorithm. In a universe without intelligent beings, all that’s occurring is just a system governed by the laws of physics and biochemistry. There’s only cause-effect relationships, and while these causal relationships can be described in algorithmic terms, they themselves are not algorithms.
In Anticipatory Systems, Robert Rosen differentiates between natural systems and formal systems. A natural system is any physical system that exists within the universe, either created by nature or humans. Just as a forest is a natural system, so is a car or a computer. A formal system, on the other hand, is created by an observer measuring and articulating a natural system. These can be expressed by using forms of notation like mathematics, logic, and music. Formal systems aim to represent natural systems, and how well it does so is determined by the accuracy of the predictions it generates. If a prediction is discovered to be true when some experiment is performed on the natural system, then we can surmise that our formal system accurately represents that natural system. If not, then we must determine which aspect of our representation is incorrect so that it can be rectified.
An algorithm belongs to the world of formal systems, not natural systems. It relies upon observation and representation to achieve the desired outcome. If we don’t get the outcome we are interested in, we tweak the algorithm. We fix the bugs in the computer code, we reduce the amount of salt we add, or we make the water warmer. Our experience interacting with the outcome, whether software or bread, is what informs us about whether the algorithm is appropriate or not.
Organisms are not algorithms, they are physical systems undergoing various physiological changes. Though we can articulate physiological processes as algorithms, they nonetheless will always belong to the domain of physical reality, not formal systems. Hunger is an experience, blood pressure is the relationship between the heart and arteries, and wolf populations are fluctuating quantities of individuals with hearts and sensations of hunger. Hormones are chemicals, atoms which bind together based on the laws of physics. There are no steps, procedures, or descriptions without an observer who is able to translate their experiences of interacting with the physical world into representations of it.
To believe that organisms are algorithms places ourselves and other animals on the same plane as computers, which is subversive and dangerous. It reduces what it means to be a living being with subjective experiences, motivations, and a rich biological heritage. We may be imperfect animals with biases and compulsions, but we are not calculators or a series of logic-gates. Unlike computers and other artifacts, we have motivations which have been selected for throughout evolution for the sake of survival and reproduction. A computer does not care about anything, it merely performs the operations it has been programmed to execute. Though we may be able to articulate biological functions in terms of operations and procedures, these representations will remain just that, descriptions of real-world phenomena.
Works Cited
1 “Yuval Noah Harari,” World Economic Forum, accessed January 18, 2026, https://www.weforum.org/people/yuval-noah-harari/; Yuval Noah Harari, “Read Yuval Harari’s Blistering Warning to Davos in Full,” World Economic Forum, January 24, 2020, https://www.weforum.org/stories/2020/01/yuval-hararis-warning-davos-speech-future-predications/.
2 Yuval Noah Harari, Homo Deus: A Brief History of Tomorrow (Signal Books, 2017), 96.
3 Harari, Homo Deus, 97.
4 Harari, Homo Deus, 97.
5 Harari, Homo Deus, 98.
6 Harari, Homo Deus, 98.
7 Harari, Homo Deus, 99.