What Is a Human Being?

Core sentence:
Being human is primarily determined by the capacity for thought and by the brain, more than by the physical body.

Start:

As described above, a human being consists of various organs, systems, and limbs. If one organ is removed, does that person remain the same, or does he become a slightly different person? How do we determine what a person is, and what defines being human? Is it determined by behavior or by appearance?

If a person receives a new artificial hip, does that change him as a person? If he is known as an Olympic athlete, then it certainly changes his performance as an athlete, but do we therefore consider him to have changed as a human being? The same applies when the heart is replaced, and so on. How many body parts and organs can be replaced before someone is no longer the same person? If something in the brain is changed through surgery or otherwise, this generally seems to produce a much greater change in the person. It therefore remains dependent on what one considers the defining characteristic of that person.

A major difference between animals and humans is generally seen in the way humans use their brains. Through the use of the brain, humans can think about the future and the past; they can calculate and write; they can communicate with fellow humans through understandable sounds. In most of these abilities humans are more skilled than other animals. All these abilities are primarily directed by the brain and are then carried out with the help of various organs: arms, hands, voice, eyes, and so on. The major distinction between animals and humans therefore seems to be the brain.

As an example we can look at Stephen Hawking, the British physicist who developed the disease amyotrophic lateral sclerosis (ALS), which paralyzed almost his entire body except for his thinking ability. In this case Hawking was still considered the same person as before the illness, apart from the obvious physical characteristics. Is this because the defining factor for Hawking was his intellectual capacity?

Would this have been different for Usain Bolt, the Jamaican sprinter, if his intellectual capacity had declined to a low level while his sprinting performance had remained unchanged?

All things considered, a person as a human being seems to be determined primarily by his brain. Or as the title of the book by Swaab states: “we are our brain.” When we consider it this way, an anecdote comes to mind that was told by a philosopher and goes as follows:

An old man of advanced age whose body has become so weak that he does not have long to live, but whose intellectual capacity is still excellent, has a conversation with an athletic young man. He says to the young man: “I do not have long to live, but you are still young, handsome, athletic, and have your whole life ahead of you. You are almost perfect, but the only drawback is that your intellectual ability—and you were born with this entirely through no fault of your own—is not very remarkable. Since I am at the end of my life, I no longer have much use for my brain, and therefore I propose to have my brain transplanted into your head and yours into mine. Your quality of life would then increase significantly, and for me it would make little difference.”

What the young man replied is not known, but it is an interesting thought exercise (Einstein: “Gedankenexperiment”) to determine who the person is after the transplantation.