What type of respect do we owe to the person? The answer depends on whether man is “nothing but a pack of neurons,” as DNA discoverer Francis Crick writes, a “computer made of meat,” in the provocative words of artificial intelligence proponent Marvin Minsky, or a creature possessing a “soul, the seed of eternity we bear within ourselves, irreducible to the merely material,” which “can only have its origin in God,” as the Catechism teaches.¹

Aristotle asserted that all living creatures have souls, and that “[w]e can dismiss the question of whether the soul and body are one; it is as though we were to ask whether the wax and its shape are one.”² Accordingly, the body is the wax while the soul is the shape, the form. A plant’s vegetative soul can only act on itself, enabling it to live and grow. An animal’s sensitive soul enjoys both vegetative and sensitive powers; it acts on things accessible by its senses, such as food that it smells and touches. Among physical creatures, only man is endowed with a rational, intellectual soul. His soul can connect with things not accessible by the senses, through the power of the intellect. Furthermore, man’s soul is immortal; it is in our immortality and our rationality that we embody the image of God.³

If God stamped his divine image into us by thus ensouling us, then we ought to see evidence in our soul’s intellectual powers. Indeed, we find that creatures with rational souls (humans) have intellectual abilities which creatures without rational souls lack.

An ape spots an approximately spherical object hanging from a branch; having seen thousands of its type before in this part of the forest, the ape recognizes the food, quickly grasps and eats it. Some argue that human understanding is much like the ape’s: a calculation based on generalization of past sensory experience. While the ape senses the roundness of the fruit it consumes, the human sees that it is approximately, but not precisely, a sphere. How is it that while no one has ever seen a perfect sphere, the human mind has an idealized concept of it? Such abstract understanding of a universal is unique to the human mind.

Understanding universals is key to the moral reasoning which sets humans apart. We do not blame the lion for slaughtering its fellow lion; the lion cannot conceive of justice as a universal concept. Nonetheless, we blame man for killing man, because through his intellect man can transcend himself and his sense perceptions. He sees justice, not with his eye, but with his mind, and he can align his behavior with moral expectations. The human capacity for moral reasoning is so significant that Charles Darwin noted, "Of all the differences between man and the lower animals, the moral sense or conscience is by far the most important."⁴

Aristotle and Aquinas called the intellect a power of the human soul. This power enables man to fathom abstract concepts, universals. Thus empowered, man can override his impulses when they conflict with universal values which he champions. He can eat carrots instead of chocolate for his health, and he can be merciful to enemies. The cleverest ape cannot do any of this, and lacking human intellect, he will never know it.

If we forget the foundation of our human dignity-- our immortal, intellectual souls-- we risk reducing the human being to a purely material entity, or to a mere beast. This reduction blots out our respect for the dignity of the elderly, the unborn, and the unwanted; viewed as mere bodies or beasts, their disposability is justified by society. We must insist on a complete understanding of our human nature: a body whose form is the intellectual soul, a seed of eternity created in the image of God.