Intellectual Power

Mortimer J. Adler BY MORTIMER J. ADLER

The Aristotelian and Thomistic doctrine concerning the intellect asserts that the human intellect is an immaterial power, in contrast to all the powers of sense, imagination, and memory that are embodied in the sensitive organs, together with the human brain.

For example, the eye and brain are the organs of vision. We see with them, and one cannot see without them. The action of these organs constitutes vision. But when we think intellectually while we cannot think without action on the part of our brains, we do not think with them. The action of the brain may be a necessary, but it is not a sufficient cause of our intellectual performance. Thought involves the action of an immaterial power, the intellect, although this cannot operate by itself.

That is the Aristotelian and Thomistic view of the matter. Of course, for materialists and all those who are optimistic about artificial intelligence machines, there is only an analytic distinction, not an existential one, between mind and brain. Materialists hold that every aspect of human thinking at the highest intellectual levels is explained by neurophysiological research — if not yet, then in the future. Eventually, if not now, knowledge of the brain’s structure and its electrochemical action will be able to account for such activity.

It is generally recognized that human beings differ in the degree of their power to think conceptually and intellectually. Einstein, as a theoretical physicist, had that power to a much higher degree than most human beings do. What is true of Einstein is true of other great mathematicians and theoretical physicists. But when, after Einstein’s death, his brain was taken out of his head and examined, it was found to be no more in its gross weight than, and also no different in structure from, the brains of ordinary human beings. Comparisons of the brains of other so-called intellectual geniuses have shown the same lack of physical distinction. Hence the antimaterialist is justified in thinking that brains alone cannot account for high intellectual performance.

Even if the activity of the brain is necessary for such performance, some added cause must be posited to account for it; and according to Aristotle and Aquinas that must be an immaterial power — the intellect.

Aquinas sought for an explanation of the fact that some individuals can think intellectually better than others. In the first part of the Summa Theologica, in Article 7 of Question 85, he explicitly asked whether one person can understand the same thing better than another person can. He answered this question affirmatively by saying that some men have bodies of better disposition, and their intellects have, as a result, a greater power of understanding — that is, a higher degree of intellectual power. We see, he went on, that “those who have delicate flesh are of apt mind.” This occurs in the powers of which the intellect has need in its operation. Those in which the sensitive, imaginative, and remembering powers are better disposed are also better disposed to understand.

In saying this, Aquinas did not think he was abandoning his view that, unlike the senses and the imagination, the intellect is an immaterial power. Even though its operation may depend on such bodily powers as those of the senses and the imagination, such dependence is quite consistent with the thesis that the intellect is immaterial and cannot be reduced to the action of the brain. The brain is not the material organ of intellectual thought, as eye and brain are the physical organs of vision. There is no organ of intellectual thought, nor as far as we know can such thoughts [concepts/universals] be accounted for in purely physical terms.


The Moral Liberal recommends Mortimer J. Adler’s, The Great Ideas: A Lexicon of Western Thought


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Mortimer Jerome Adler (1902 – 2001) was an American philosopher, educator, and popular author. As a philosopher he worked within the Aristotelian and Thomistic traditions. He worked for Columbia University, the University of Chicago, Encyclopædia Britannica, and Adler’s own Institute for Philosophical Research. Adler went on to found the Great Books of the Western World program and the Great Books Foundation. He founded and served as director of the Institute for Philosophical Research. He also served on the Board of Editors of Encyclopædia Britannica from its inception and became its chairmen. Spearheading the fifteenth edition of Britannica he was instrumental in the major reorganization of knowledge embodied in that edition. He founded the Paideia Program, a grade-school curriculum centered around guided reading and discussion of difficult works (as judged for each grade). With Max Weismann, he founded the Center for the Study of The Great Ideas. He also served along with Max Weisman on the Board of Directors of Jonathan Dolhenty’s Radical Academy.