ABSTRACT
III. L E C T U R E T H R E E2. The resurrection of old errors and confusions: materialism and Platonism.a. Hobbes13 revived once more the ancient error of the atomists: that there is only matter in motion, the matter being reducible to small particles differing only in quantity, the motion being entirely local. Although Hobbes used an Aristotelian vocabulary, even to the extent of distinguishing faculties, his treatment of psychological phenomena as results of atomic motions in sense-organs and brain, had the familiar consequences of materialism: sensationalism in the analysis of cognition, and the denial of intellect; the dominance of the passions in the analysis of motivation, and the denial of free-will. Hobbes was the first behaviorist. (T o his credit it must be said that he was inconsistent with his principles. Despite his analysis, Hobbes recognized that man is rational both in his account of knowledge and of political behavior.)b. Descartes14 revived once more the Platonic error of dualism, and exaggerated that error, making a sharper separation between body and soul by identifying soul with mind or intellect [39]. As a result:(1) The substantial unity of man was destroyed, and psychology became burdened with the impossible riddles of the mind-body relation, of sensation and free-will as interactions between incommunicable substances, etc. (Where Hobbes had written Of Man, Descartes wrote of the soul.)(2) The basic terms of psychological analysis (power, habit, act) were obscured or lost because the soul was viewed as a complete substance rather than as the formal principle of the composite and the proximate source of its powers. Furthermore, since its essence was identified with the operation cf thought, the soul could have no variety of parts or powers. (It became impossible, therefore, for Descartes properly to distinguish cognition and appetite, the spheres of intellect and will. Psychology became almost exclusively an analysis of cognition and ignored or distorted the non-cognitive and non-rational 13Human Nature (1650); Leviathan (1651), Pt. I, Ch. I-II. 14 Rules for the Direction of the Mind (1628); Meditations (1641), especially I and V I; Principles of Philosophy (1644), especially Pt. I; The Passions of the Soul (1645-6) in Philosophical Works, ed. b y Haldane and Ross, Cambridge, 1931: v .I . 76
III. 2. b . ( 2) L E C T U R E T H R E Easpects of human nature. This ultimately led to the confusion of psychology with epistemology.)(3) As sensationalism was the error of Hobbes’ materialism, so intellectualism or intuitionalism was the characteristic error of Cartesian Platonism. Ideas are both innate and directly known, rather than acquired by abstraction from sense, the instruments not the objects of knowledge. (A materialism consistently carried out reduces man to the grade of brutes; the Platonic error goes to the opposite extreme of elevating the soul to the substantial and cognitive level of angels. The Aristotelian conception of man as a rational animal is the mean between these errors; as St. Thomas so frequently says, man is on the boundary between the material and the spiritual worlds.)(4) Physiology, animal and human, became the science of mechanical automata.14®c. Locke, Berkeley and Hum e15 followed Hobbes in his sensationalism, but also made the Platonic error of treating “ideas,” i.e., sensations or impressions, as the objects of knowledge.(1) In these three writers, the confusion of psychology with epistemology reached its height. They tried to give a genetic account, an inventory, and a critical evaluation of the contents of the mind. Thus, Locke stated his problem to be “the original, certainty and extent of human knowledge.” 19 As a result of the simple error of treating sensations or ideas as that which {id quod) is known instead of as that by which {id quo) man knows what {quid) he knows of that which he knows (physical things), the development of psychological doctrine from Locke to Hume ended in subjectivism, phenomenalism and positivism.(2) In all three, it is not man but the mind, cognition, or 14aLa Mettrie in UHomme Machine (1748) showed how readily Cartesianism became mechanistic materialism. V d . also Holbach and Helvetius.15 Locke, An Essay Concerning Human Understanding (1690); Berkeley, A Treatise Concerning the Principles of Human Knowledge (1710); Hume, Trea tise of Human Nature (1739-40); Enquiry Concerning Human Understanding (1748).16 Op. ch., 1, 1 , 1f 2.
