Homo Deus: A Brief History of Tomorrow

Harari posits a transformative vision of humanity’s progress and future challenges. He begins with a metaphorical awakening of humanity at the dawn of the third millennium, reflecting on the historical nightmares of war, famine, and plague. Harari notes that for centuries, these three calamities dominated the human agenda, seemingly insurmountable and integral to existence. However, he argues that recent decades witnessed a pronounced shift: These foes have been transformed from unmanageable natural forces into challenges that, while not entirely solved, are now largely within humans’ control.

The Quest for Control: Overcoming Famine, Plague, and War

Harari details each of these three scourges, starting with famine. Historically, famine was a constant and deadly threat, with entire societies living close to starvation. He illustrates this with accounts from past famines, like the French famine of 1694, where people resorted to eating unclean sources of food due to extreme scarcity. Yet, in the contemporary world, Harari observes a significant change: Advancements in technology, economics, and politics have created a safety net, turning natural disasters into opportunities for trade and aid, thus reducing the prevalence of famine. While hunger and malnutrition persist, they no longer lead to the mass deaths of the past.

The discussion then moves to plagues and infectious diseases, humanity’s second great enemy. Harari recounts the devastating impact of historic plagues like the Black Death and smallpox. The transformation in this arena has been even more dramatic. Through medical advancements like vaccinations and antibiotics, as well as improved hygiene and medical infrastructure, humanity has gained unprecedented control over infectious diseases. Harari highlights the eradication of smallpox and the containment of recent epidemics like SARS and Ebola as examples of this power. He acknowledges the ongoing threat of AIDS but notes the significant progress made in managing the disease.

Lastly, Harari addresses the decline of war. He observes that for most of human history, war was a constant and accepted part of life. However, the 20th century brought a decrease in war-related deaths and a shift in the perception of war. He attributes this change to the advent of nuclear weapons, which made war between superpowers a mutually assured destruction, and the rise of the knowledge-based economy, which values intellectual resources over territorial conquest. While regional conflicts persist, the idea of large-scale war between major powers has become increasingly inconceivable.

Beyond Survival: Pursuing Immortality and Happiness

With the traditional threats of famine, plague, and war receding, Harari asks what new challenges will occupy humanity’s agenda. He anticipates a focus on ecological sustainability and raises the possibility of humanity pursuing more ambitious goals like immortality, happiness, and even divinity. Harari’s vision is one where humanity, having overcome its oldest enemies, now faces the challenge of what to do with its newfound powers and potential.

Harari explores the evolving human pursuit of immortality and happiness. He begins by suggesting that the 21st century may witness humanity’s earnest quest for immortality, building upon humans’ successes against famine and disease. This quest, Harari argues, reflects the supreme value of contemporary culture: the sanctity of human life. He contrasts this with historical attitudes where life was often seen as a means to a metaphysical end.

Harari examines how death, traditionally personified and accepted as a metaphysical inevitability, is now increasingly viewed as a technical problem with potential solutions. He asserts that modern science and culture don’t see death as imbuing life with meaning; rather, they see it as a problem to be solved. This shift in perspective has led to a growing focus on overcoming physical causes of death, such as heart failure or cancer, through scientific advancements.

The pursuit of immortality is gaining traction, according to Harari, particularly in the fields of genetic engineering, regenerative medicine, and nanotechnology. He cites figures like gerontologist Aubrey de Grey and inventor Ray Kurzweil, who are outspoken about defeating death and achieving eternal youth. This ambition, however, extends beyond the realm of science into broader societal and ethical implications. Harari raises critical questions about the impact of significantly extended lifespans on societal structures, such as family, work, and governance.

Harari then shifts to discussing the quest for happiness, another major human endeavor. He notes that despite incredible advances in living standards, happiness levels haven’t risen accordingly, suggesting a “glass ceiling” of happiness. This leads to the exploration of the psychological and biological factors influencing happiness. Harari posits that happiness is more about the balance of bodily sensations than external conditions. He discusses the transient nature of happiness and how humans’ biochemistry, which evolved to increase chances of survival and reproduction, plays a key role in this.

The pursuit of biochemical happiness has led to increasing reliance on psychiatric drugs and other forms of biochemical manipulation, a trend Harari views with caution. He argues that to achieve genuine, long-term happiness, humanity may need to re-engineer its biological makeup, a task that presents immense challenges and ethical considerations.

Envisioning Homo Deus: The Future of Human Evolution

In the conclusion of the chapter, Harari explores the concept of humans evolving beyond their current capacities, essentially becoming god-like, or Homo deus. This section highlights three potential paths for this transformation: biological engineering, cyborg engineering, and the creation of non-organic beings.

Harari explains that biological engineering could potentially enhance human capabilities by genetically modifying human DNA, hormones, and brain structure. This transformation would mean that future humans, or “godlings,” might differ from people as much as people differ from Homo erectus.

Cyborg engineering involves merging the human body with technology, like bionic limbs or nanorobots. This would grant humans abilities far beyond their organic limitations. Harari points out that such a cyborg could exist simultaneously in multiple places, merging mind and machine in unprecedented ways.

The third path is the creation of entirely non-organic beings. This involves replacing biological neural networks with artificial intelligence (AI), allowing life to move beyond the limitations of organic chemistry into uncharted territories.

Harari highlights the difficulty in predicting the future, especially with the potential for such revolutionary changes in biotechnology. The future of humanity, shaped by these advancements, may go beyond humans’ current understanding or expectations. He emphasizes that the goal is not just to predict the future but also to liberate humans from the past and reimagine what is possible.

The chapter also touches on the ethical and societal implications of these advancements. Harari suggests that the pursuit of immortality, bliss, and divinity, while rooted in humanist ideals, may also lead to the obsolescence of Homo sapiens as people know them. The technologies that promise to elevate human capabilities to divine levels might also render humans irrelevant in comparison to more advanced beings or AI.

The chapter concludes by reflecting on the nature of change and the historical transformations of human civilizations. Harari suggests that the potential fall of humanism and the rise of a new “god-like” species could be seen not as a catastrophe but as a natural progression in the history of human evolution. This section of the book thus serves not only to predict a possible future but also to challenge an understanding of humanity.