This blog post examines how far cyborg engineering can extend the definition of humanity and explores the future changes technology will bring to humankind.
Humans have long feared death and fundamentally pursued immortality. This fear stems not only from the terror of facing the end that is death, but also from the anxiety that the meaning of one’s lived life will vanish. Consequently, humans have battled disease, famine, and natural disasters for ages, analyzing the causes of death and seeking ways to overcome them throughout this process. Through these efforts, humanity has taken a step further beyond the boundary of life and death, pursuing a better life.
The development of 20th-century medicine brought revolutionary change to humanity. Advances in science and technology meant that epidemics and famine were no longer the greatest threats to humanity, and an era arrived where war itself became unthinkable. This does not mean that people suffering from epidemics, famine, or war have completely disappeared. Rather, it signifies that humanity has made these problems sufficiently controllable, thereby gaining the ability to extend life. In other words, what was once seen as an inevitable, natural death has now begun to be perceived as a technical problem.
Now, humanity seeks not merely to extend life, but to overcome death itself. Recently, Google Ventures has invested 36% of its assets in life extension projects. Furthermore, the prominence of fields like genetic engineering and nanotechnology clearly demonstrates that modern science has made overcoming death a core focus. This phenomenon extends beyond mere corporate investment strategy. It suggests that modern humanity’s aspiration to conquer death is gradually becoming a feasible goal.
Yuval Noah Harari argues in his book Homo Deus that “since death is the result of technical problems of the body, there must be a technical solution, and therefore death can be overcome.” The solutions he proposes are biotechnology, cyborg engineering, and the synthesis of non-organic entities. This perspective is revolutionary in that it moves beyond the past perception of death as an inescapable fate, instead recognizing death as a problem and viewing it as something that can be solved.
Among these, cyborg engineering refers to the fusion of the organic human body with inorganic devices. For example, implanting a mechanically superior prosthetic leg in a person who has lost a limb could be one such application. Another example includes technology that implants electrodes in the brain to operate machinery on the other side of the globe. Before such cyborg engineering becomes commercially viable, I believe it is necessary to first redefine the category of ‘human,’ specifically ‘to what extent can something still be considered human?’ Without this, ambiguous cases would arise where applying laws or social agreements currently applied to organic humans becomes problematic.
For instance, we must define whether a body part replaced by a machine is considered part of the person or merely an object they possess. This goes beyond mere philosophical debate. Real legal and social issues could arise. It could lead to questions like whether damaging it should be punished as attempted murder or as property damage. Furthermore, even if one achieves immortality through cyborg engineering, if they can no longer be called human, the question arises: does immortality truly hold meaning? Therefore, it is necessary to clearly define the scope of humanity and prevent the adverse effects cyborg engineering may bring.
To address these issues, I propose attempting a new definition of humanity based on Yuval Harari’s Homo Deus. First, I propose one assumption for defining humanity. According to Yuval Harari, cyborg engineering is a discipline premised on the organic brain serving as the body’s command center. Thus, it involves preserving the organic brain while replacing body parts like arms and legs with machines, synchronizing them to move according to the brain’s signals. If machines were to possess consciousness and mind like an organic brain, there would be no need for the organic brain to serve as the command center. Therefore, to maintain the premise of cyborg engineering, we will assume that mechanical algorithms cannot possess consciousness and mind like an organic brain.
Based on this assumption, entities operated by non-organic algorithms, such as artificial intelligence, cannot be considered human. Consequently, if a person’s body remains unchanged while only their brain is replaced with a machine, that entity can no longer be called human. Even if it possesses an organic body, it lacks consciousness and mind—the very essence of human identity. Conversely, could a person whose brain remains unchanged but whose entire body is replaced with machines truly be called human?
According to the hypothesis, even if the entire body is replaced with machinery, it can still be called human because consciousness exists. However, replacing all parts of the body except the brain with machinery means, conversely, implanting a human brain into a machine so that the machine operates based on the organic brain rather than existing algorithms. For example, if a brain is implanted into a car, allowing it to speak through the radio speakers and move by rolling its wheels, it should also be called human. Furthermore, once this becomes possible, humans wouldn’t necessarily need to remain confined to a single body. When traveling to another country, one could implant their brain into an airplane; for work, into a laptop; for cooking, into a gas stove. They could move and use various bodies as needed.
Even if the algorithm of an organic brain is considered important as the essence of human identity, the meaning of that algorithm ultimately changes depending on the hardware it operates on. That is, the algorithm and the body are in a reciprocal relationship. Therefore, having an organic brain does not mean the form of the body is unimportant. As in the example above, an entity whose body can change fluidly and deviates significantly from the universal human form is difficult to call human.
One solution to this problem is to divide the body into organic and non-organic parts, considering only the organic portion as the body. For example, we do not consider a human riding in a car to be a single entity with the car. Just as we say a human is riding in a car, a person wearing a prosthetic leg does not have the prosthetic become part of their body. It is more accurate to view the human’s organic body as using a non-organic prosthetic. In the case of a human whose entire body has been replaced by machines, only the organic brain could be called the body.
To summarize, we should call Homo sapiens possessing an organic brain “human,” and the scope of that individual should extend only to the organic body parts operated by the brain. This definition, as mentioned in the introduction, can prevent controversies arising from the ambiguous scope of the body by providing a clear definition. This definition presupposes that mechanical algorithms do not possess consciousness. It also has the limitation of not being able to account for cases where only part of the brain is mechanically replaced. Nevertheless, the attempt to define humanity in preparation for the coming era of immortality is clearly necessary.
