Science. January 27, 2016

Transcription

1 Science January 27,

2 2 Anaxagoras For our purposes, Anaxagoras is interesting as a follower of Parmenides and Zeno. Many of the fragments from Anaxagoras appear to be paraphrases of Parmenides. E.g.: Even though these things have been dissociated in this way, it is right to recognize that all things are in no way less or more (for it is impossible that they be more than all), but all things are always equal. (Simplicius, Commentary on Aristotle s Physics ) He accepts a plurality of basic entities, and six (!) basic principles: Basic entities: 1. Objects and their parts 2. Basic Ingredients 3. Portions Principles: 1. There is no coming to be or perishing 2. There are many different types of basic ingredients. 3. There is a portion of everything in everything. 4. Each thing is most plainly those things of which it has the largest portions. 5. There are no smallest portions. 6. Mind is unmixed with other things and has the following functions: 1. It knows all things 2. It rules all things 3. It sets all things in order 4. It causes motion 4. Seeds 5. Mind

3 3 Democritus and Leucippus Leucippus is the originator of atomic theory, and the teacher of Democritus. Leucippus... did not follow the same route as Parmenides and Xenophanes concerning things that are, but seemingly the opposite one. For while they made the universe one, immovable, ungenerated, and limited, and did not even permit the investigation of what-is-not, he posited the atoms as infinite and ever-moving elements, with an infinite number of shapes, on the grounds that they are no more like this than like that and because he observed that coming-to-be and change are unceasing among the things that are. Further, he posited that what-is is no more than what-is-not, and both are equally causes of things that come to be. His associate, Democritus of Abdera, likewise posited the full and the void as principles, of which he calls the former what-is and the latter what-is-not. For positing the atoms as matter for the things that are, they generate the rest by means of their differences. These are three: rhythm, turning, and touching, that is, shape, position, and arrangement. (Simplicius, Commentary on Aristotle s Physics ) By contrast with Parmenides, Zeno, and the earlier monists, atomic theory posits an indefinite number of eternal, indivisible entities that make up everything else. In one sense, this is a clearly pluralistic view: how many things are there in the universe? Indefinitely many. But in another sense, this view could be considered a kind of monism, since the atoms are all uniform, unchangeable, and imperceptible, and all the same kind of stuff. More confusingly, the atomists contrast atoms with the concept of void, which, if considered a category of being, would make their view either pluralistic, or dualistic. So we have a puzzle: what kind of theory is atomism? It is uncontroversially mechanistic (as opposed to the teleological views of Plato and Aristotle). No thing happens at random but all things as a result of a reason and by necessity. (Aetius ) Our sources for their views are mostly Aristotle and commentators on Aristotle.

4 4 The Progress of Greek Natural Philosophy In the Presocratics we find a focus on a search for foundational explanatory principles of nature, and the development of method(s) of inquiry. We begin with philosophers attributing explanatory power to natural forces (elements) rather than the gods, making knowledge of the world and wisdom a public matter rather than esoteric and divinely revealed. Parmenides and Zeno offer powerful philosophical arguments against plurality and change. Leucippus and Democritus offer an objection to this in a defense of a new theory: atomism, which is, in one sense, pluralistic. Aristotle gives us another way of defending change against the arguments of Parmenides and Zeno.

5 5 Aristotle s Terminology The textbook has a glossary, which can help us follow Aristotle s introduction of many new terms. E.g., Coincident: Aristotle recognizes two sorts of coincidents: (1) G is a coincident of F if (a) G belongs to F IN ITS OWN RIGHT, but (b) G is not the ESSENCE of F; e.g., a triangle has two right angles in its own right, but this is not the essence of a triangle. (2) G is a coincident of F if (a) G belongs to F, but (b) F is not essentially G. In this case F's being G does not follow from the essence of F. What does Aristotle mean by Subject, and Substance?

6 6 Physics I The Starting Point of Natural Knowledge Knowledge is achieved in any inquiry into a subject by understanding the principles or elements of the subject. So the first task in natural science is to determine its principles. Method of inquiry: 1. Begin with what is better known and more perspicuous to us. 2. Proceed from (1) to what is better known and more perspicuous by nature. (1) is less perspicuous by nature. (2) is more perspicuous by nature. What are these things that we should start with?

7 7 Physics I The Starting Point of Natural Knowledge Most perspicuous to us at first: Inarticulate Wholes Elements and principles (of these wholes) come to be known from them. The universal includes many things as parts, so it is a sort of whole. So, in gaining knowledge we must move from universals to particulars. This is analogous to the relation between names and their accounts. Why? A name signifies a sort of whole, indefinitely. But, a definition states particular properties. E.g., a circle may have any number of properties (i.e., the name circle picks out all circles), but a particular circle (or kind of circle) has specific properties.

8 8 Physics I Aristotle s Account of Coming-to-Be and Perishing Recall Parmenides argument against the possibility of things either coming to be or perishing. How does Aristotle s counter-argument go? There s a general argument, but Aristotle provides a specific example. First Conclusion: nothing that exists is naturally such as to act or be affected in just any old way by the agency of just any old thing; nor does something come to be just any old thing from just any old thing, unless you consider coincidents. Major Conclusion: all the things that come to be naturally are either contraries or from contraries. (188b25) 1. If musical is a coincident of the not-pale (or dark) thing, then something cannot come to be pale from being musical. 2. If musical is not a coincident of the not-pale (or dark) thing, then something cannot come to be pale from being musical. 3. Therefore, being musical is not the cause of something coming to be pale. Something comes to be pale from being not-pale. (in the sense of being dark, or between dark and pale). Something comes to be musical from being not-musical (in the sense of being unmusical, or between musical and unmusical). Is this a good argument? What does it mean?

9 9 Physics I Aristotle s Account of Coming-to-Be and Perishing Things don t perish into any old thing. E.g., the pale thing does not perish into the musical thing (except coincidentally). It perishes into the not-pale thing (specifically: the dark thing, or between pale and dark). The same is true in other cases as well. Why? Because the same account applies to things that are not simple, but composite (188b10) 1. Whatever is ordered must necessarily come to be from something disordered and what is disordered from something ordered. 2. Whatever is ordered must necessarily perish into disorder, and not into just any old disorder, but into the one opposed to that order. Why?

10 10 Physics I A Puzzle 1. A subject seems to be a principle of, and prior to, what is predicated of it. 2. Therefore, if a principle were said of any subject, then it would itself have a principle. 3. So, a principle must not be said of any subject. 4. One substance is not contrary to another. 5. So, contraries are not the substance of anything that is. [i.e., not prior to a substance] 6. Therefore, we must assume some other nature as subject for contraries. What does Aristotle mean by subject and predicate in this argument? What is the relationship between the subject/predicate relationship and the principle/substance/contrary relationship?

11 11 Physics I A Solution If we take the two previous arguments to be correct, then we must assume a third thing as subject. So, the Presocratics who take the whole universe to be according to a single principle are on to something! Something intermediary between the elements seems more reasonable, because fire, earth, air, and water are essentially involved with contrarieties. So Aristotle seems to accept a monistic first principle. But he denies that it can be any of the four elements. So it must be something intermediate or intermediary. Why does Aristotle think this? Does Aristotle successfully show that coming-to-be and perishing are possible?

12 12 Physics I Aristotle s Account of Coming To Be Aristotle s account follows his method of inquiry, beginning with what is common to all, and then moving to specific cases. He divides the things that can come to be into simple and compound cases. A man becomes musical. A not-musical thing comes to be musical. A not-musical man comes to be a musical man. Compound because a thing comes into being, and something comes to be it. simple thing coming to be <F> : the man, and the not-musical thing. In some cases the simple thing remains. E.g., a man remains a man. In other cases it does not. E.g., a musical thing (either simple or compound) does not remain so. compound : the thing that comes into being, and what comes to be that thing. Sometimes: not only something comes to be F, but also it comes to be F from being G. E.g., a man comes to be musical from being not-musical. But we don t say this for all properties of the man. Conclusion: In every case, there must be some subject that comes to be <something>; even if it is one in number, it is not one in form, since being a man is not the same as being an unmusical thing One thing <that comes to be> remains, and one does not remain. The thing that is not opposite remains. (190a15)

13 13 Physics I Aristotle s Account of Coming To Be Something comes to be F from being G in at least the following ways: The G doesn t come to be F, where the G does not remain. E.g., <a man> comes to be musical from being unmusical, but not <the unmusical comes to be musical> from a man. In cases where the G does remain, we can speak the same way. E.g., a statue comes to be from bronze, but not bronze comes to be a statue. If something comes to be F from being G, where G is opposite to F and G does not remain, then something comes to be F from being G and G comes to be F. E.g., the man comes to be musical from being unmusical, and the unmusical one comes to be musical. We say the same about compounds: the musical man comes to be musical from being an unmusical man, and the unmusical man comes to be musical. Only substances are said to come to be without qualification. In other cases, there must be some subject that comes to be <something>. There must be a subject underlying change, because a substance is the only thing that is never said of another subject, whereas everything else is said of a substance. (190a30-35) Substances also come to be from some subject. E.g., plants and animals come to be from seed. Ways that things can come to be without qualification: change of figure, addition, subtraction, composition, alteration. What comes to be is composite: something comes into being, and something that comes to be that (which is either subject or opposite). E.g., unmusical is opposite, man is subject. Lack of figure, shape, and order is the opposite, bronze, stone, or gold the subject.

14 14 Physics I Principles Suppose there are causes and principles of natural things from which these primarily are and have come to be. It follows that everything comes to be from the subject and the shape. E.g., musical man is composed of man and musical. The subject is one in number but two in form. The contrariety is a coincident. The form is one, predicated of the subject. In one way there are two principles, in another, three: 1. In one way, contraries. 2. In another, not contraries; the subject is something different (not a contrary).

15 15 Physics I Aristotle s Reply to Parmenides, et. al.: Those who were the first to search for the truth philosophically and for the nature of beings were diverted and, so to speak, pushed off the track by inexperience. They say that nothing that is either comes to be or perishes. For, they say, what comes to be must come to be either from what is or from what is not, and coming to be is impossible in both cases; for what is cannot come to be (since it already is), while nothing can come to be from what is not (since there must be some subject). And then, having reached this result, they make things worse by going on to say that there is no plurality, but only being itself. They accepted this belief for the reason mentioned. We reply as follows: The claim that something comes to be from what is or from what is not, or that what is or what is not acts on something or is acted on or comes to be anything whatever, is in one way no different from the claim that, for instance, a doctor acts on something or is acted on, or is or comes to be something from being a doctor. So it is also clear that coming to be from what is not signifies this: coming to be from it insofar as it is not. (191b1-10)