The intellect is an immaterial or spiritual cognitive faculty. A faculty is that by means of which man performs mental or conscious operations, and a cognitive faculty is concerned with the mental operation of knowing (see faculties of the soul). Immaterial or spiritual signifies something not intrinsically dependent on matter, not requiring matter as an auxiliary cause for its existence or for its operation. Vision requires material organs, the eyes, as an auxiliary cause; without them the soul cannot see. Thinking does not require a material cause, but is caused directly by the soul, through the intellect. And since thinking is an immaterial or spiritual operation, the faculty by means of which it occurs, the intellect, is itself immaterial. (see immateriality.)
Intellect is sometimes considered to be synonymous with intelligence. Yet it is better to distinguish between the two. The term "intelligence" is being used more and more to designate the mind of animals, in addition to that of man. Since the animal mind is a material power, intrinsically dependent on matter, it is essentially different from the human intellect.
Existence of the intellect. No one denies that man knows. But some philosophers—usually materialists, sensists, or positivists—deny that man possesses immaterial knowledge that is essentially different from sense knowledge. Hence they deny also the existence of the intellect as defined above. Their principal argument invokes the fact that the human brain is required for thinking, since any serious impairment of man's brain makes thought impossible. This fact is undeniable and shows that the brain is somehow involved in thought. But Thomists maintain that the brain is a necessary condition, not a cause, of thinking. A necessary condition is one that enables a cause to produce its effect, without actually contributing toward the production itself. A cause, on the other hand, contributes in a positive manner toward the production of the effect. For example, electricity is the cause of light in a bulb, while closure of the switch is a necessary condition (see causality).
Brain and Immateriality. That the brain is not a cause of thinking can be explained through the principle: As a being acts, so it is (agere sequitur esse ). The brain is a material substance, concrete, visible, tangible, singular, extended, existing in space and time, contingent, and not necessary; its effects must exhibit these characteristics also. And indeed, a brain tumor and a brain wave do. But man's intellectual operations show different characteristics. His ideas are universal, not limited to space and time, not extended, not concrete. Many of man's judgments are necessary, true at all times, in all places, in all circumstances; for example, whatever is, is; everything that comes to be has a cause; two plus two make four. Even ordinary judgments contain an element of necessity. Thus, if one says "It is raining," this proposition is not itself necessary; but, having affirmed that it is raining, he also has implicitly affirmed: "If it is raining, it cannot be not raining." The universality of man's ideas and the necessity (at least hypothetical) of his judgments cannot derive from a material organ such as the brain. They require a power that is, to some extent, beyond time and space, free from the contingency of matter. This immaterial, spiritual power is called the intellect.
Another proof for the immateriality of the intellect is derived from man's capability for reflection. When man knows, he also knows that he knows. In his awareness of being aware, subject and object coincide. This cannot occur in a purely material being. The luminous self-presence of man's act of reflection is thus proof that he possesses an immaterial, spiritual power of thinking.
Image and Concept. A source of objection against this doctrine is the confusion that frequently arises between image and concept. This received classical expression from George berkeley: "Whether others have this wonderful faculty of abstracting their ideas, they best can tell; for myself, I find indeed I have a faculty of imagining, or representing to myself, the ideas of those particular things I have perceived … whatever hand or eye I imagine, it must have some particular shape and colour. Likewise, the idea of man that I frame to myself must be either of a white, or a black, or a tawny, a straight or a crooked, a tall or a low, or a middle-sized man" (Principles of Human Knowledge, Introd., § 10). Bishop Berkeley here confuses the image with the idea. It is true that every man one imagines must be a determinate individual, but it is not true that every man one thinks of must be such. This is apparent in the quotation itself, where mention is made of "whatever hand or eye." These words have meaning—some thought or concept corresponds to them in the objector's mind—yet they apply to all possible hands and eyes, each of which must indeed have "some particular shape and colour," without the intellect's making explicit reference to such shape and color.
Object of the intellect. To know a faculty well one must know its object, what it can know, and from what point of view it knows. This requires that the material and formal objects of the human intellect be ascertained. A further distinction has traditionally been made between its proper and adequate objects. The proper object of the intellect refers to the things it knows naturally and easily—the material objects in man's environment: other men, animals, plants, houses, and the like. Accordingly, the proper material object of man's intellect comprises all objects that can be perceived by the senses. The senses, however, perceive the color, sound, shape, distance, and the like, of these objects, while the intellect recognizes them for what they are. The eyes note the color of a dog and the ears hear its bark, but the intellect knows that this is a living being, an animal, a dog. This "whatness" or quiddity of material objects is the proper formal object of the human intellect.
Being and Truth. Yet the scope of the human intellect extends beyond the realm of material objects. The fact that one speaks of material objects implies that he knows of other objects that are not material. What is required in any object, in order for it to be knowable by the human intellect, is that it be, or, at least, that it be able to be. Hence the total or adequate object of the intellect is being in all its extension, whether material or immaterial. Now the intellect knows such being from the viewpoint of its truth or intelligibility. Accordingly, while the adequate material object of the intellect is being, its adequate formal object is truth or intelligibility.
Of every reality man knows he can affirm that it is. Yet, although being is its object, what his intellect continually meets is not being, but rather beings. In other words, in the repeated affirmation, "This is, that is," the predicate "is" happens always to be too wide for the subject to which it is applied. This explains why man continues to look for new things to know. No object of experience fills the full capacity of his intellect. Man is always in search of an object that will entirely exhaust his power of affirmation. He strives, albeit unconsciously, for the knowledge of a reality of which he can simply say: This is, without any restriction or limitation. In other words, his intellect strives toward knowledge of the unlimited being, of God.
Knowledge of God. Left to his own devices, however, man can reach only a deficient and imperfect knowledge of God. He knows Him, through analogy with creatures, as the all-perfect came that must possess eminently all perfections found in finite realities. This analogical, inadequate knowledge of God is the highest knowledge of Him that reason can offer to man.
Revelation, however, promises infinitely more—a knowledge of God as He is in Himself, in His inner essence, in the ineffable mystery of His triune inner life. Such knowledge is clearly beyond the powers, and even beyond the expectations, of the human intellect. It requires a transformation of that intellect, raising it above its natural state and supernaturalizing it. Sanctifying grace produces this transformation. It gives to the baptized person the supernatural gift of faith, which is the power of knowing, although darkly, God as He is in Himself. In the elect, during the next life, this gift of faith gives way to the beatific vision; as St. thomas aqui nas explains it, the human intellect sees the divine essence "through the divine essence itself; so that in this vision the divine essence is both that which is seen and that by means of which it is seen" (C. gent. 3.51).
Operation of the intellect. Since the intellect is an immaterial faculty, it cannot be influenced directly by material reality. The problem arises then as to how intellectual knowledge originates in man. One answer is that, as material objects affect the sense organs, so sense knowledge influences the intellect. But this answer implies that the intellect is a material power. The senses can be influenced by extramental reality because, like that reality, they are material. But how can the intellect, an immaterial power, be influenced by the senses and receive from them a material content?
The intellect, of course, may be influenced by immaterial causes. This is why some have held that its ideas come directly from God; such, with various modifications, was the teaching of plato, St. augustine, des cartes, and malebranche. But this theory contradicts human experience and leads to consequences that are inacceptable (see knowledge, theories of).
If ideas cannot come from the senses and do not come directly from God, the intellect must receive them from itself. The intellect, therefore, acts upon itself and receives from itself. Thus we distinguish in it two faculties, an agent intellect and a passive or possible intellect. The agent intellect impresses ideas upon the possible intellect.
Agent intellect. Where does the agent intellect find these ideas? St. Thomas holds that it derives them from sense experience. The agent intellect actively abstracts the species from the phantasm and impresses it upon the possible intellect (see abstraction; species, intention al). Phantasms are the highest products of the combined senses. In modern terminology they correspond to perceptions, or images; as material forms of knowledge, they represent single, concrete, material objects.
The passage from this concrete, singular phantasm to the abstract, universal concept is sometimes explained as follows: Viewing the phantasm of a particular tree, the intellect leaves aside all the individualizing, concrete features (e.g., the tree's size and color) and considers only the general, universal features. But how can the agent intellect distinguish between general and individual features, keeping the former and dropping the latter, unless it knows all of them? This seems to suppose that the intellect directly knows the material phantasm, a position that Thomists generally deny. Again, how can a material phantasm affect an immaterial intellect? It is often maintained that the agent intellect, acting as the principal efficient cause, uses the phantasm as an instrumental cause to impress the abstracted universal idea upon the possible intellect (see instrumental causality). But it would seem that a material tool can produce only material effects, even when used by an immaterial agent. How then can it affect an immaterial reality?
An alternative, and possibly more acceptable, explanation of ideogenesis focuses on Aquinas's teaching that man never uses ideas without turning to the corresponding phantasm. Man knows ideas (or rather, what they represent) only in the phantasm. This seems to imply no actual extraction of the idea from the phantasm. Otherwise it would be difficult to see why, once man has separated the two, he cannot use the idea independently of the phantasm.
The substantial unity of man, in fact, implies not only the unity of body and soul but also that of sense and intellect (see soul-body relationship). As the soul is to the body, so the intellect is to the senses. The soul does not hover over the body, but rather is in the body. Likewise the intellect does not stand above the senses; it is in them. To speak of a "passage" from sense to intellectual knowledge is to fall into Cartesian dualism and admit that both the body and the soul have their own representations of the object. Actually there is only one knowing subject, composed of both body and soul. As the body never acts without being animated by the soul, so the senses never act without being animated by the intellect. This means that the intellect is already at work in the formation of the phantasm (see cogitative power). It animates the formation of the phantasm, and this activity produces the universal idea. The impressed species of the intellect is this dynamic relationship between the intellect and the phantasm.
Expressed species. The agent intellect is like a powerful searchlight, of which St. Thomas says that it is always "in act." By itself it does not give knowledge. As soon as sense knowledge crosses its beam, however, the corresponding idea is generated. In this sense the phantasm is truly an instrumental cause—it gives the light of the intellect something to illuminate.
When an object comes within reach of the agent intellect, that object is seen as something, a being, a reality. The intellect then consciously expresses the relation it has attained unconsciously in the impressed species. This is the expressed species, the word, the verbum. In such an expressed species the object is grasped intellectually. Most Thomists hold that this expressed species is the concept, attained by simple apprehension. Others maintain that it is an "affirmed concept," a concept embedded in a judgment, although often only an elementary judgment. According to this view, being is given in judgments, possibles in concepts. Hence the expressed species of the intellect, through which man gets his first intellectual contact with reality, is the elementary judgment that the intellect utters to itself (thus, the word) whenever it knows reality.
Acts of the Intellect. The first two acts of the intellect have already been mentioned, that is, simple apprehension and judgment. Once man possesses a certain number of concepts and judgments, he can then explicitly compare them, discover their relationships, derive one from the other, associate them with each other, and the like. This work constitutes the third act of the intellect, known as reasoning.
In explaining how knowledge perfects the knower, St. Thomas notes: "… knowing beings are distinguished from non-knowing beings in that the latter possess only their own form; whereas the knowing being is naturally adapted to have also the form of some other thing, for the species of the thing known is in the knower" (Summa theologiae 1a, 14.1). As explained above, this does not mean that the species is a self-sufficient picture of the object, for St. Thomas also teaches that man cannot know the object without reverting to the phantasm (Summa theologiae 1a, 84.7). Yet knowing things means to some extent becoming these things, since man has in him, for every object he knows, a phantasm and a species, the latter being understood as a dynamic relation of the intellect to the former. By animating the phantasm of the object, the intellect intentionally becomes that object. In this sense, the acts of conceiving and of judging perfect the human intellect.
In addition, reasoning perfects the intellect in other ways. First, by discovering connections between realities, it makes man aware of the structure, the order, and the harmony of the universe. This allows him also to direct his activities in the right way, according to the order of importance of goals and purposes. Again, having detected an underlying order and hierarchy in the universe, he discovers also its basic orientation and finality, and thus is led to acknowledge its Designer and Creator.
Differences in intellectual ability. The nature and operation of the human intellect has been the main concern here. Above the human intellect there are, however, higher and more perfect intellects. From revelation one knows of the existence of angels (see angels, 2. theolo gy of). Philosophically these are conceived to be pure forms, in no way dependent on matter (although they do have some relationship to the material universe). They are, therefore, basically intellects and wills. Whatever they know has been communicated to them at their creation. Angels know through infused species, which, coming directly from the Maker of all, give them certain and clear knowledge of reality. Thus their knowledge is more perfect than man's. Since angels differ from each other in ontological perfection, each constituting an original, unique grade of being, their intellects too differ in acuity, penetration, and extension of knowledge.
Above all created intellects stands the Uncreated Intellect, God. God does not "have" an intellect. He "is" Intellect, as He is every other pure perfection substantially. As the Self-Subsistent Intellect, God knows Himself perfectly and comprehensively. He also knows in Himself, as they are in themselves, all existing and possible creatures.
Differences in intellectual abilities among men seem to be due not to the spiritual intellect itself, but to its relation to the body. Hence they are differences of intelligence, more than of intellect.
See Also: knowledge, process of; understanding (intellectus); intuition.
Bibliography: thomas aquinas, Summa Theologiae 1a, 14, 79, 84–87. j. f. donceel, Philosophical Psychology (2d ed., rev. and enl. New York 1961). r. e. brennan, Thomistic Psychology (New York 1952). b. lonergan, Insight: A Study of Human Understanding (New York 1957). j. maritain, Distinguish to Unite, or the Degrees of Knowledge, tr. g. b. phelan from 4th French ed. (New York 1959). a. marc, Psychologie réflexive (Brussels 1948). j. marÉchal, Le Point de départ de la métaphysique, 5 v. (2d ed. Paris 1949). k. rahner, Geist in Welt (2d ed. Munich 1957).
[j. f. donceel]
The rationalism of medieval Jewish philosophy is manifest in its doctrines of intellect. Seen as both an incorporeal, universal heavenly substance and as a personal psychic faculty, intellect is both within man and without; it is viewed as the source and goal of all knowledge, man's bridge to the upper world and to everlasting happiness.
The creative aspect of intellect is concentrated in a heavenly substance, which is regarded as the place of all universal ideas. It is called Intellect or Mind in the neoplatonic tradition (see *Neoplatonism) and Agent or Active Intellect in the Aristotelian (see *Aristotle and Aristotelianism), where it is the last of ten such intelligences and responsible for the sublunar sphere of earth (see *Cosmology, *Emanation; Plotinus, Enneads 5:9, 1–9; Solomon ibn Gabirol, Mekor Ḥayyim (Fons Vitae), 2:8, 20; 3:26; Israeli, "The Book of Substances," in: A. Altmann and S.M. Stern (eds.), Isaac Israeli (1958), 85ff.; Maimonides, Guide, 2:4). Both are viewed as proceeding from God, entrusted by Him with the shape and destiny of the world; in more Aristotelian terms, they are the formal and final causes of earthly things. As such the neoplatonic Intellect and the Aristotelian Agent Intellect in their respective traditions play the role assigned to Logos in *Philo and the Word in Christianity.
Man's intellect is related to this heavenly substance as a further emanation or individualization of universal Intelligence. Thinking is viewed as a process whereby the individual intellect and the object of intellection are both "illuminated" by the "light" of the universal intellect, leading to knowledge of the ideas latent in objects of our perception. Man's intellect thus "recreates" the intelligibles underlying all reality, bringing them and himself from potentiality to actuality. During intellection, the subject becomes one with its object, intellect becoming its intelligible (as said of Aristotle's Unmoved Mover, or God, in Metaphysics, 12:9, 1074b 34; and see On the Soul 3:4, 5). The philosophers prefer to call this relation "conjunction" (Arabic ittiṣāl, Hebrew devekut) rather than "union," which is the mystics' term, emphasizing thereby its impermanent nature and the retention of individuality by man and, particularly, by the universal Agent Intellect. The total, transcendent nature of the latter is generally considered beyond man's comprehension. Among the ideas that man can know for a certainty are self-evident principles of reason, or the laws of logic, and the rational structure of the world. They lead man to the knowledge of God's existence and His relation to man and the world. Such ideas place even relatively simple religious belief in an intellectual framework. Religious teachings are then seen as either obviously or ultimately rational, and the intellect to a large degree becomes the arbiter of faith (see particularly Saadiah Gaon, The Book of Beliefs and Opinions, introd. 5; 2:13; 3:1–4).
Human intellect is analyzed as a faculty of the soul and regarded as one of the internal senses. It is that which receives the already semiabstracted perceptions, known as phantasms, from the soul's intellectually disposed imagination or memory, and brings the process of abstraction and generalization to completion. The explanation of the process of disengagement from matter is facilitated for the later philosophers by their subdivision of the Aristotelian concept of active and passive states of intellect into a number of stages. Chief among these are the "hylic" (material), or "potential," intellect, viewed either as an incorporeal substance (following *Themistius) or as a disposition of the body to receive intelligibles (following *Alexander of Aphrodisias); the intellect "in act" and its counterpart, intellect "in habitu," which express an intellect that has become under the influence of the Agent Intellect actual and experienced; and the "acquired" intellect, representing intellectual perfection and conjunction with the world of eternal substances (a world also identified with the angelic realm; see F. Rahman's summary of the influential views of al-Fārābī and Avicenna, Prophecy in Islam (1958), 11–29; and see Levi ben Gershom's survey, Milḥamot ha-Shem, Part i).
Philosophers disputed whether this last stage can be reached by natural processes and whether personal identity is retained in it, vital issues relating to man's happiness and immortality. Despite opposition from traditional circles, the trend toward acceptance of a unified intellect and the loss of individuality in intellection, discernible in the thought of the Muslim philosopher Ibn Bājjah (see *Avempace) and of *Maimonides (see Guide 1:72; 74, 7th method), is pronounced in the writings of the Averroists. For *Averroes, whose influence upon such late figures as *Moses of Narbonne and *Levi ben Gershom was great, the potential intellect is a disposition of the Agent Intellect itself, only accidentally related to imaginative forms and man. Conjunction of the acquired intellect with the Agent Intellect, therefore, is seen as possible even in this life, and even though man, as commonly understood, thereby surrenders himself to universal being.
A. Altmann, in: H.A. Wolfson Jubilee Volume, 1 (1965), 47–87; I. Efros, in: jqr, 33 (1942/43), 133–70; O. Hamelin, La théorie de l'intellect d'après Aristote et ses commentateurs (1953), 3–72; A. Ivry, in: jaos, 86 (1966), 76–85; H.A. Wolfson, in: Journal of the History of Ideas, 22 (1961), 3–32; Guttmann, Philosophies, index s.v.Intellect. add. bibliography: H. Davidson, Alfarabi, Avicenna and Averroes on Intellect (1992); Sirat, History of Jewish Philosophy in the Middle Ages (1985), index s.v.Intellect; D. Schwartz, "The Quadripartite Division of the Intellect in Medieval Jewish Thought," in: jqr. 84:2–3 (1993–94), 227–36; R. Jospe, Torah and Sophia: The Life and Thought of Shem Tov ibn Falaquera (1988), ch. 4.
[Alfred L. Ivry]
So intellection understanding. XVII. — L. intellectual XIV (whence intellectualism XIX, intellectualist XVII). — L. intellectuality XVII. — late L. intelligent XVI. — prp. of L. intellegere, -ligere lit. choose among, f. INTER- + legere gather, choose. (So intelligence XIV. — (O)F. — L.; hence intelligencer XVI). intelligentsia XX. — Russ. intelligéntsiya — Pol. inteligiencja — L. intellegentia. intelligible XIV.
in·tel·lect / ˈintlˌekt/ • n. the faculty of reasoning and understanding objectively, esp. with regard to abstract or academic matters: he was a man of action rather than of intellect. ∎ the understanding or mental powers of a particular person: his keen intellect. ∎ an intelligent or intellectual person: sapping our country of some of its brightest intellects.