Understanding is a familiar occurrence in everyone's experience, but it is difficult to define philosophically. As D. hume has said, "It is remarkable concerning the operations of the mind, that, though most intimately present to us, yet, whenever they become the object of reflexion, they seem involved in obscurity" (An Enquiry concerning Human Understanding [Oxford 1902] 13). The difficulty is accentuated when one tries to communicate his thought to another, for he cannot present his mental operation for inspection, and it becomes especially acute in crossing the barrier between modern language and medieval. This article therefore begins with modern philosophical usage in English and in German (on which English often depends), then gives a systematic exposition of the notion of understanding according to a modern writer, Father B. J. F. Lonergan, and concludes with a discussion of the Thomistic concept of intellectus.
Philosophical Usage. In modern usage, the substantive "understanding" may refer to the cognitional faculty (e.g., the understanding as opposed to the will), or to the developed state of the faculty (e.g., he showed great understanding), or to the content of the act of understanding (e.g., my understanding of the matter is …). But all these usages evidently derive from the verbal use, to understand, for which the Oxford English Dictionary gives as first definition: to comprehend, to apprehend the meaning or import of, to grasp the idea of. As the common man would say: to get the point, to catch on. Nor is there the slightest difficulty about this use of the word; everyone with a minimum of education knows what is meant by "I do not understand the question."
English. When the word enters English philosophy it has at first a rather vague sense. For John locke, it is evidently interchangeable with mind (Of Human Understanding, The Epistle to the Reader, par. 1), and is defined as the faculty of perception, where the objects of perception are listed as: ideas in the mind, the meaning of signs, and the agreement or disagreement of ideas (ibid. 2.21.5). Elsewhere it is stated that the word "idea" comprehends "whatsoever is the object of the understanding" (1.1.8). Locke's work is more concerned, in fact, with ideas than with understanding, and ideas themselves are not sharply differentiated from other cognitional elements, including "phantasm, notion, species, or whatever it is which the mind can be employed about in thinking" (ibid. ). Hume proposes "to enquire seriously into the nature of human understanding," to conduct "an exact analysis of its powers and capacity" (op. cit. 12), but he goes on to speak of "an accurate scrutiny into the powers and faculties of human nature" (13) and to state his hope of drawing "a mental geography, or delineation of the distinct parts and powers of the mind" (14); whence it appears that understanding for Hume is almost synonymous with what is most specific in human nature or with mind.
German. For nearly two centuries philosophical usage of the English word has had to reckon with the German counterpart, especially as used by I. Kant and W. dilthey. A direct concern with the faculty itself and its activity rather than with its objects appears in Kant who, moreover, sharply distinguishes Verstand and Vernunft, usually translated as "understanding" and "reason," respectively. Understanding is the power that forms concepts; it is the faculty of the rules ordering the intuitions of sense into the provisional unities of the categories; it is the faculty of the possible. Reason is the power that systematizes, the faculty of the principles ordering the less-inclusive rules into the absolute unities of the illusory transcendental ideas; it is the faculty of the necessary. Understanding clearly has an orientation to experience and the content of sense; reason tries to transcend experience. (See J. M. Baldwin, Dictionary of Philosophy and Psychology [3 v. New York 1901–05]; "Kant's Terminology" by J. R[oyce].)
With Dilthey understanding receives a still more restricted sense; confined by him to the human sciences, it corresponds to explanation (Erklärung ) in the natural sciences, is distinguished from knowledge, and is closely linked with interpretation. Man knows what causes a rainbow, but he understands his friend's anxiety. Understanding is insight into the human mind, sympathetic entrance into the interior states of other persons, grasping the meaning in human institutions and in history.
For M. Heidegger's notions of existential understanding as projecting the possibilities of the subject and of interpretation as understanding becoming itself, see his Being and Time, tr. J. Macquarrie and E. Robinson (New York 1962) 182–195.
Lonergan's Exposition. The following more systematic exposition follows a work by B. J. F. Lonergan, Insight. A Study of Human Understanding (New York 1957).
Act of Understanding. Understanding, according to Father Lonergan, is the central and pivotal act in the human cognitional structure formed basically of experience, understanding, and judgment. Here experience has a very precise sense; it means the presentations of sense and the representations of imagination: what is seen, heard, imagined, etc. In this sense it is merely an animal activity, but in man there supervenes on mere experience the new factor of wonder. Man expresses his wonder first in questions of the type, Quid sit? (What is it?). But wonder is not so much a question as the source of all questions, a dynamism and a need. The need is for understanding, for insight into the presented materials, for getting hold of the idea, grasping the quiddity, finding the intelligibility immanent in the content of experience. Understanding, however, does not of itself satisfy the need of intellect, for its ideas are essentially hypothetical and what man seeks is the real. So there intervenes a second type of question, An sit? (Is it?). Is my idea correct? The reflective process that answers this question ends in judgment of existence, knowledge of the real. Thus, experience is explanatorily defined as what is presupposed and complemented by inquiry and understanding, understanding in turn as what is presupposed and complemented by reflection and judgment (Insight, 333–334). The three levels form a dynamic structure with the two questions, Quid sit? and An sit? manifesting the dynamism that effects the shift from first level to second and from second to third.
On the second level itself, understanding is to be distinguished from definition, concept, hypothesis, theory, and system, i.e., from everything that expresses the content of the act of understanding. In short, understanding, as preconceptual, is distinguished from the formulation of understanding or, as St. Thomas Aquinas would say, from the verbum incomplexum that proceeds from it. The difference here is between the intelligibility grasped in the particular instance and the intelligibility disengaged from the particular instance and set free in the universal concept. In order to understand, man forms an image to think the matter out, or he constructs a model, or he draws a figure on paper, or he studies the data. The question is always put with regard to what man experiences; understanding always finds its primary object immanent in experience. "The act of understanding leaps forth when the sensible data are in a suitable constellation" (Lonergan, Theological Studies 7  362). Thus understanding occurs with regard to an instance. The concept or formulation, on the contrary, is set free from the instance; it has become a universal. The difference between understanding and the explicit formulation of the universal is best epitomized in the contrast between artist and scientist. The artist certainly understands something but his understanding is tied to the sensible presentation (the work of art), nor has he full possession of his understanding: often enough he cannot tell just what his idea is. The scientist aims at disengaging the idea, taking possession of it, discovering its implications and applications, and drawing it into systematic relationship with other ideas.
Types of Understanding. Again, within understanding there occur various types, based not on specific differences in the object (physics, chemistry, etc.), but on different procedures in the subject. There is (1) commonsense understanding, which relates things to a person through his senses (the motion of the Sun as describing an arc over his head); (2) scientific understanding, which relates things to one another in abstraction from their relation to the observer as such (the motion of the Sun in relation to other bodies in the solar system); (3) heuristic understanding, which anticipates the idea by grasping the kind of activity through which it will occur; and (4) determinate understanding, which reaches the idea by carrying out the activity. These are four more important types of direct understanding; in contrast there is inverse understanding, which has as its object irrelevance as such; it grasps the irrelevance to direct understanding of the here and now, of constant velocity, of the nonsystematic in statistical laws, etc., and has fertile applications throughout empirical science, philosophy, and theology. Finally, the term is extended to judgmental activity on the third level of cognitional process; it is then called reflective understanding, again named in contrast to direct.
Differentiation from Other Notions. With respect then to Locke and Hume, Lonergan makes understanding in the strict sense a very specific activity; he distinguishes it from the level of sensation and image on one side, from the level of reflection and judgment on the other, and on its own level from the concepts that formulate it. With respect to Kant, Lonergan assigns understanding a more precise relationship to experience: it is indeed the power that forms concepts and subsumes instances under rule, but it does so because it is directly related to sensible materials through the question they raise; moreover, it is not restricted to a priori forms but is a ranging power, potens omnia fieri. With respect to Dilthey, Lonergan would admit the riches of meaning embedded in the data of the human sciences but would insist that these data are intelligible in the same way as other data, and that this intelligibility is in principle subject to formulation and its own scientific explanation. In short, understanding would "confer a basic yet startling unity" (Insight, ix) on all fields of human inquiry, those represented by Kant and Dilthey as well as others.
Thomistic Concept. For St. thomas aquinas, the term intellectus has many meanings (see L. Schütz, Thomas-Lexikon [2d ed. Paderborn 1895; repr. Stuttgart 1958] 406–413). (see angels, theology of; intellect.) In the context of modern discussions of the notion of understanding, however, two meanings assume particular significance, namely, that of understanding as a habit of first principles and that of understanding as a cognitional activity in some way related to reason.
Habit of First Principles. As a speculative habit of the intellect, understanding is to be distinguished from the habits of science (scientia) and of wisdom. The basis for this distinction is the following: "A speculative intellectual virtue perfects the speculative intellect in its consideration of truth, for this is its good. But truth can be attained in two ways: in one, as immediately (per se ) grasped; in the other, as grasped through an intermediary (per aliud ). What is grasped immediately has the status of a principle and is immediately perceived by the intellect. Thus the habit that perfects the intellect for this type of consideration of truth is called understanding; it is the habit of principles" (Summa theologiae 1a2ae, 57.2). Explaining the nature of this habit in another place, St. Thomas notes: "Intellectus is not here taken to mean the intellective power itself, but a particular habit by which man naturally knows indemonstrable principles in the light provided by the agent intellect. And the name is well chosen, for principles of this kind are known immediately once their terms are understood. As soon as one knows what a whole is and what a part is, he immediately recognizes that the whole is greater than the part. It is said to be intellectus from the fact that it reads within (intus legit ) by grasping the essence of the thing" (In 6 eth. 5.1179).
The habit of first principles in the speculative order, as thus explained, is called understanding in English usage; for a fuller explanation, see first principles. Corresponding to these, there are also indemonstrable principles in the practical order; the habit of such principles may also be called understanding, though it is more frequently designated by the transliteration from the Greek συντήρησις (see synderesis); which came, by accident, to mean the light of conscience.
Ratio and Intellectus. Considerable discussion surrounds the significance of St. Thomas's usage of the term "ratio" as opposed to intellectus. Studies by P. rousselot, J. Peghaire, P. Hoenen, and Lonergan yield the following account: At the basis of all reasoning (ratio ) is the simple act of understanding, the Thomist intelligere or the Aristotelian νοε[symbol omitted]ν. It has its object in the image whence in English one speaks of "insight into the phantasm." Thomas Aquinas could say that whenever man tries to understand (intelligere ) he forms images (phantasmata ) in which he, as it were, inspects (inspiciat ) the solution (Summa theologiae 1a, 84.7), and Aristotle could assert that the noetic faculty (νοητικόν) understands (νοι[symbol omitted]) the forms in images (ἐν το[symbol omitted]ςφαντάσμασι—Anim. 431b 2). But equally all reasoning has its term in understanding; man reasons in order to understand better, to develop his understanding. Understanding (intelligere ), says St. Thomas, is the proper act of the human soul, perfectly demonstrating its power and nature (Summa theologiae 1a, 88.2 ad 3). But this does not eliminate ratio as the human characteristic, for ratio is the imperfect form of intelligere found in man: "Human intellect is essentially intellect-in-process or reason" (Lonergan, Theological Studies 7  378; 8 39–46).
The tendency found often enough in St. Thomas to distinguish intellectus and ratio more sharply can possibly be attributed to the predominance of the logical viewpoint he inherited. But he adverts also to a context that is not merely logical, that anticipates modern science to include empirical discovery and escape the confines of deduction (see Hoenen).
The effect of this analysis is to reduce the opposition between ratio and human intellectus to its proper proportion, to underline the basis in sense and imagination of every human concept (even man's concept of God), and to link Aristotle and Thomas Aquinas with what physics and other modern sciences are so obviously doing. It also gives a clear analogy for discussing both theological understanding and the understanding of mysteries (donum intellectus ) that St. Thomas made a gift of the Holy Spirit (Lonergan, "Theology and Understanding").
Thomistic usage in this regard differs from that of modern philosophers. John Dewey, for example, makes understanding correspond to reason in the way conditional, reflective, mediate knowledge does to comprehensive, self-sufficing knowledge (Baldwin, Dictionary …, "Understanding and Reason"). K. Oehler agrees that the discursive faculty is διάνοια or ratio, the intuitive faculty νόησις or intellectus. In German usage up to Kant, Vernunft is ratio and Verstand is intellectus; but Kant reversed the usage, attributing to Verstand the constitution of the categories and to Vernunft the knowledge of ideas. This usage, except in A. schopenhauer and some others, prevailed in Germany, though in the mid-20th century there was concern about the arbitrary character of the choice and its lack of correspondence with the work of modern physics (see Die Religion in Geschichte und Gegenwart, 7 v. [3d ed. Tübingen 1957–65] 6:1364–65).
See Also: apprehension, simple; insight; intuition; reasoning.
Bibliography: b. j. f. lonergan, "The Concept of Verbum in the Writings of St. Thomas Aquinas," Theological Studies 7 (1946) 349–392; 8 (1947) 35–79, 404–444; 10 (1949) 3–40, 359–393; "Theology and Understanding" Gregorianum 35 (1954) 630–648. e. m. mackinnon, "Understanding according to Bernard J. F. Lonergan, S.J.," Thomist 28 (1964) 97–132; 338–372; 475–522. w. dilthey, Meaning in History, ed. h. p. rickman (London 1961). h. g. gadamer, Die Religion in Geschichte und Gegenwart, 7 v. (3d ed. Tübingen 1957–65) 6:1381–83. j. wach, Das Verstehen, 3 v. (Tübingen 1926–33). m. magnusson, Der Begriff "Verstehen" im exegetischen Zusammenhang … (Lund 1954). d. dubarle, "Esquisse du problème contemporain de la raison," in La Crise de la raison dans la pensée contemporaine (Paris 1960) 61–116. j. peghaire, Intellectus et Ratio selon Saint Thomas d'Aquin (Ottawa 1936). p. hoenen, "De origine primorum principiorum scientiae" Gregorianum 14 (1933) 153–184. p. rousselot, The Intellectualism of Saint Thomas, tr. j. e. o'mahony (London 1935).
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