Autor: Vertin, Michael -- Mehrere Autoren: Lonergan Workshop, Volume 8

Buch: Lonergan's "Three Basic Questions" and a Philosophy of Philosophies

Titel: Byrne, Patrick H., Insight and the Retrieval of Nature

Stichwort: Aristoteles: Natur; 4 Ursachen; Definition: Bewegung

Kurzinhalt: Thus Aristotle's four causes turn out to be distinct yet legitimate ways of answering the question, "Why is it changing the way it is?"

Textausschnitt: 1.3 Immanent Nature and the Four Causes

13c After this preliminary specification of form and matter as his principles of Nature, Aristotle turned to develop his account of those principles further. He observed that natural change is overwhelmingly regular, recurrent, harmonious, and no attentive person can fail to notice this fact. And yet, the regularity of Nature's recurrences does not completely exclude the reality of chance as a feature of Nature. These facts of regularity and of chance in combination led to his assertion that "all things existing by nature appear to have in themselves a principle of motion and of rest" (192bl4-15) and "no thing by nature acts on, or is acted on by, any other chance thing" (188a32-34). In other words, the regularities in Nature could not be wholly accounted for by the chance sequences of external influences. There is simply too much regularity in "all that changes," Nature, to be accounted for by external influences alone. Plants of a given species are never exposed to exactly the same sequence of moisture, light, heat, and nutrients. None the less, they exhibit remarkably identical growth patterns. Hence, there emerges a second meaning of the term "nature"-the "nature" not of the whole but of some thing. "Nature is a principle and a cause of motion or rest in that to which it belongs primarily" (192b21-22).1 The "natures" of things are what are known in grasping the fuller reasons for the regularities in Nature. These "natures" are primarily the forms. They determine to a large extent what sorts of changes a thing will characteristically undergo; and along with the matters, they determine what sorts of movers can move the thing to such changes. (Fs)

14a But because the matter of a given form can also be the matter of other forms as well, movers can "violently" move the matters to new forms which disrupt the natural form's organization. The potted plants, sleeping cats, and pieces of furniture alike are moved across the room, not in virtue of their forms, but because their matters happen to also have the potential for that motion; a bird's wing is severed in a way not explained by the bird's form, but in virtue of properties relating the flesh and bones to the severing instrument. Thus the changes which actually occur are determined by the particular sequences and constellations of the matters and forms which constitute both the movers and the moveds. (Fs)

15a These observations clarify something about the composition of the Physics which can lead to confusion. In Book A Aristotle developed two principles of nature: matter and form; but in Book B he developed the four causes. It would seem, therefore, that there are two parallel and distinct explanatory schemata relevant to the science of nature. However, the famous four causes are in fact the same two principles taken from various viewpoints. The "that from which as a constituent" (or material cause) is matter in the sense discussed above. The formal cause is form as discussed above, from the viewpoint of integral explanation of the thing's characteristic recurrent motions. The "that from which change or rest first begins" or efficient cause is a substance (ousia) but primarily with respect to its form. In other words, whatever is changed receives its form from the ousia which already "has" that form. Aristotle's example is of the parent as cause of the child. The form of humanity of the parent is indispensable for the transformation of matter not yet human into the form of a human being. And finally, the "that for the sake of which," telos or final cause, is not some inner impulse directing growth. It is the form which finally results when the motion continues on to completion (194bl5-26). (Fs)

15b Thus Aristotle's four causes turn out to be distinct yet legitimate ways of answering the question, "Why is it changing the way it is?" Biological examples are particularly illuminating. To "why is it sprouting leaves along its branches rather than only at their tips?" one could legitimately answer in four different ways. First, "The growth pattern characteristic of this species is thus and so," is an answer via the form (formal cause) of the moved thing. Again one could answer, "Because it has absorbed sufficient and appropriate nutrients with which to do so," and the answer would be in terms of matter (material cause). Or one could answer, "Because it has developed from a seed produced by the plant of such and such a species," which designates the form, definition, of the principal mover of the moved plant (efficient cause). Finally one could answer, "It is part of the sequence of developments which lead to the mature adult plant" (final cause). In the latter three cases, form as the answer to the question is construed in three different ways: the form as overall integral organization of characteristic behavior; the form of that which first has form and thereby stimulates a reorganization of the moved, either in whole or in part; and finally as the developmental sequence specified by means of its ideally completed form. (Fs)

16a From these observations, Aristotle's definition of motion follows fairly straightforwardly: "Motion is the actuality of the potential qua potential" (201all-12). The motion of growing is occurring just as long as what can be transformed into the form of a mature plant continues to be, but has not yet been, so transformed. Nor does the mature plant stop moving (living) once it has become mature; it is no longer doing the moving called "growing," but it does exhibit motions of replenishing, reproducing, and so on, which are all moving just as long as relevant matters are in the process of being, but have not yet been, given the relevant form. Form, then, is the fundamental determinant of change for Aristotle. (Fs)