This small volume (205 pages, including index) presents a forceful case for the existence of a distinct human nature that makes us fundamentally different from any other kind of animal.
Intellect was published in 1990, when its author was 87. It represents the views of someone who had spent a long life learning, thinking, teaching, and writing. Adler, a maverick of 20th-century philosophy who stopped trying to get the attention of his academic colleagues in 1977 and decided to write only for the general reader, draws on the tradition of thought that stems from Aristotle. Against all the modern and postmodern philosophers, psychologists, anthropologists, neurologists, and artificial-intelligence researchers, who mainly hold that, since our experience and mental powers arise from the brain, there is no basic difference between humans and other animals, Adler asserts that the human intellect is unique on Earth, and that, although the brain is necessary in order for the intellect to manifest, it is not sufficient. The intellect, which gives us our powers of conception, judgment, and free choice, is immaterial and not a mere product of brain activity, as, say, our sense of hearing is.
Moving quickly over the terrain, the author describes what the intellect is, discusses what he regards as the errors of philosophy and science in losing a grasp of this classical concept, enumerates the special powers of the intellect, and finishes with a short section on virtue and vice, or the proper and improper use of the intellect.
So what is the intellect? It is the mental power to form and use general concepts: the power of abstraction. It allows us to reason deductively and to create and use language with which to communicate. Adler is at pains to demonstrate that animals do not possess these abilities in even the most rudimentary degree. He maintains that rats, for instance, that can recognize triangular shapes in order to press a button for food, are making use only of perceptual abstraction. In other words, the rat recognizes triangular shapes as similar, but has no notion of “triangularity” as such. No rat will ever know what a triangle is. No rat will ever be able to define triangle or to read Euclid.
When I reached the final part where Adler shows how intellect gives rise to the virtues and vices, and allows us, because of its fundamental freedom, to lead lives of virtue (if we so choose) and thus of dignity as human beings, I was excited and inspired. Among other things, it’s not easy to find such a short, cogent, clear, and authoritative account of virtue and vice, and in my opinion this part of the book alone is worth its purchase price.
Do I buy the author’s argument? I’m not sure. His breadth of learning and depth of thought and experience in this area are vastly greater than mine. My own philosophical training, such as it is, has been mainly Buddhist. In the Buddhist view, all sentient beings have fundamentally the same mind. It is this that allows reincarnation as different kinds of beings in different lives. All sentient beings want to be happy and to avoid suffering. Different beings have different aptitudes and powers, but in the nature of things there cannot be any categorical difference between them.
Adler’s view, which he expressed in his earlier book Difference of Man and the Difference It Makes, is that if we lack a clear understanding of the difference between human and animal, then we can never have any principled reason to treat humans differently than we treat other animals. If we round up and slaughter cattle because it suits us, there is no fundamental reason why we shouldn’t round up and slaughter people if it suits us. The morality of it is the same.
There’s no easy answer to this. I think the Buddhist reply might be that instead of transferring our cruelty from animals to humans, we might think about transferring some of our human kindness toward animals.
But Intellect provides plenty of food for thought. Indeed, it’s a workout for the intellect, which, for many of us, has become as flabby as our bodies. If you want to read about something that matters, give this a go.