By Dave Jarvis
January 17, 2008
The soul according to many religious and philosophical traditions, is a self-aware ethereal substance particular to a unique living being. Such traditions often consider the soul both immortal and innately aware of its immortal nature, as well as the true basis for sentience in each living being.
—Wikipedia
By the definition above, inanimate objects have no soul (such as rocks). Similarly, electrons, atoms, and molecules do not have a soul. And most people would agree that simple life forms exist without a soul (such as viruses and bacteria). What has a soul, then?
Since the soul is the basis for sentience, and sentience refers to the experience of sensation, then the types of living beings that have a soul can be further whittled down. Consider the following definitions for sensation and sense.
Sensation: A physical feeling or perception from something that comes into contact with the body; something sensed.
Sense: One of the methods for a living being to gather information about, and interact with, the world; sight, smell, hearing, touch, taste.
—Wiktionary
Any organism that can see, smell, hear, touch, taste or any combination thereof is assigned a soul. The issue of when souls are assigned revolves around a tantalizing problem: evolution.
Evolution is change in populations of organisms over generations. Offspring differ from their parents in various ways. When these differences are helpful, the offspring have a greater chance of surviving and reproducing, making the differences more common in the next generation. In this way, differences can accumulate over time, leading to major changes in a population.
—Wikipedia
At some point there existed an organism that lacked the ability to sense, ergo it had no soul. Yet through a chance mutation, when the organism replicated, its offspring changed in a way that allowed a new or existing physical structure to be used for sensing. That offspring was instantly assigned a soul.
This innocuous assignment is the crux of the problem: why does sentience separate the soul-full from the soul-less? The issue takes a twist when considering the Christian view of the soul. Christianity, and many Western definitions, marks the soul as a uniquely human trait.
The emotions and intellect of a living person, as well as that person's very life. (Thessalonians 5:23, Hebrews 4:12.)
—World English Bible Glossary
The seat of personality, the individual or person themselves, the immaterial component of a human, etc. Among Christians, dichotomists believe that a person is composed of a body and soul.
—ReligiousTolerance.org
The soul may be defined as the ultimate internal principle by which we [that is, we humans] think, feel, and will, and by which our bodies are animated.
—Catholic Encyclopedia
The immortal element in human beings sometimes regarded as our true self.
—Irving Hexham's Concise Dictionary of Religion
The principle of life, feeling, thought, and action in humans, regarded as a distinct entity separate from the body, and commonly held to be separable in existence from the body.
—Dictionary.com Unabridged
The animating and vital principle in humans, credited with the faculties of thought, action, and emotion and often conceived as an immaterial entity.
—American Heritage® Dictionary
The spiritual principle embodied in human beings, all rational and spiritual beings, or the universe.
—Merriam-Webster OnLine
The spiritual element of a person, regarded as immortal.
—Compact Oxford English Dictionary
The spiritual, rational, and immortal part in man; that part of man which enables him to think, and which renders him a subject of moral government.
—Webster Dictionary, 1913
Every human alive today owes their existence to parents: two persons (a man and a woman) who reached a sexually mature age and subsequently reproduced. Those parents owe themselves to another set, and so on back down the ancestral tree. Modern humans, known as Homo sapiens sapiens, evolved from Homo sapiens (archaic) around 100,000 years ago, who themselves descended from Homo erectus between 1.8 and 0.3 million years past, who, in turn, sprang from Homo habilis in the range of 2.5 to 1.8 million years agone.
Now Homo habilis probably looked distinctly un-human whereas Homo sapiens (archaic) likely appeared fairly human.
So if the definition for human is limited to modern humans, then it means any ancestors who lived beyond 100,000 years ago, like our distant relatives Homo sapiens (archaic), did not get a soul. While the distinction between having and not having sensory perceptions may be demonstratably clear, distinguishing modern humans and not-quite-modern humans is impossible. It would be like trying to point to the colour of yellow that divides green from orange in a rainbow.
Which leads to the question:
At what point during evolution were humans given souls?
An easy answer awaits: the soul does not exist.