I. Aristotle’s life
• Born 384 B. C.
• Originally from Stagira in Macedonia
• Student of Plato
• Teacher of Alexander the Great
• Organized a school in Athens called the Lyceum which rivaled that of Plato
• When an anti-Macedonian movement swept Athens he left to avoid being executed (different from Socrates).
II. Plato and Aristotle
A. While Plato’s philosophy is idealistic, inspiring, otherworldly and perfectionist, Aristotle’s is realistic, scientific, this-worldly and pragmatic.
B. Styles are different largely in virtue of what has survived. Plato’s dialogues survived, Aristotle’s lecture notes survived.
C. Picture of the School of Athens: Plato points up (to the Forms), Aristotle point down (at the world of our experience).
Plato vs. Aristotle on knowledge
• For Plato the model for knowledge is mathematics. For Aristotle it’s biology. What’s the difference? Biology relies extensively on observation. E. Example: Plato’s social/political philosophy defines an ideal society. He doesn’t care if it’s attainable, and even tells you how it will fall apart if it is achieved. Aristotle’s looks at actual societies to see which ones work the best. He surveys 158 constitutions and decides which ones work the best in what circumstances.
III. All men by nature desire to know
• Theory of knowledge
• A. All human beings by nature desire to know.
• Do they? Or do we only desire that knowledge that will bring us pleasure?
• Presupposes that language and thought are congruent to the structure of reality. How could we understand nature if there is no affinity between nature and our minds?
Aristotle the Common sense philosopher
• For Plato there can be no science (rational discourse) of particular things. For Aristotle there can be, in fact knowledge begins with the study of particular things. So the marker in my hand is not an object of knowledge, only belief. Aristotle found this preposterous.
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IV. There are real physical objects, by golly
• Aristotle maintains that it is a mistake to study an abstract quality in isolation form concrete exemplifications. Thus Aristotle presumes that we can know particular things. In fact, while this seems like a pretty common-sense idea, philosophers from the Eleatics (those who denied motion) to the atomists (it’s all really atoms, not particular things) to the Sophists (there’s no knowledge) to Plato (all we can really know are forms), denied this common-sense notion.
V. The presuppositions of knowledge
• Aristotle presupposes that language and thought are congruent to the structure of reality. How could we understand nature if there is no affinity between nature and our minds? Otherwise, we coudn't negotiate traffic on 59th Avenue during rush hour.
VI. Aristotle’s ten categories
• 1. What is it?
2. How large is it?
3. What is it like?
4. How is it related?
5. Where is it?
6. When does it exist?
7. What position is it in?
8. What condition is it in?
9. What is it doing?
10. How is it acted upon?
Would Plato ask these questions, and expect an answer?
VII. Aristotle discovers logic
• Logic is the science of arguments. Aristotle discovered that you could distinguish the form of an argument from the content of the argument. Aristotle put statements into categories and show how you can determine, based on the structure of an argument, whether or not the argument is valid.
VIII. The concept of validity
• 1. An argument is valid, just in case, on the assumption that the premises are true, the conclusion must be true. If an argument is valid, the internal logic of the argument is solid. The argument can only be challenged externally, but attacking the truth of the premises. Aristotle’s key discovery is that arguments can be analyzed from the point of view of their logical form, as well as from the point of view of the truth of the premises.
IX. An example of a valid argument
• 1. All dogs are mammals.
• 2. No mammals are birds.
• 3. Therefore no dogs are birds.
• No matter how you change the premises of this argument you cannot get an argument that has true premises and a false conclusion.
X. Validity is a matter of logical form (repeat this ten times).
• Validity is a matter of logical form. A valid argument can be given in favor of a false conclusion, or even in favor of a stupid conclusion. (Also repeat this ten times).
XI. This argument, for example, is valid
• 1. The moon is made of green cheese.
• 2. If the moon is made of green cheese, then the moon is made of red cheese.
• 3. Therefore the moon is made of red cheese.
• The conclusion is false, but so are the premises. If you were to retain the logical structure but change the terms of the argument, you could never get true premises and a false conclusion.
XII. Invalid arguments
Other argument forms do not reliably get true conclusions if the premises are true. There are invalid arguments.
An argument can have true premises and true conclusions and still be a bad argument because the logical structure is faulty
Ex. All beagles are dogs.
All hounds are dogs.
Therefore all beagles are hounds.
Although this argument has true premises and a true conclusion, it is nevertheless an invalid (and therefore bad) argument, because by the same logic the same argument could just as easily support the conclusion “All beagles are hounds” a clear falsehood.
XIII. Sound Arguments
• A sound argument is a valid argument with true premises.
• If the premises are true and the argument is valid, and the conclusion is guaranteed to be true.
XIV. Inductive Arguments
• Some arguments don’t have to be valid to be good.
• 1) In the past, the sun has always risen in the morning.
• 2) Therefore, the sun will rise tomorrow.
XV. First Principles
• Aristotle maintained that there were certain fundamental principles in every discipline. Although some people would like to think they can, or should, prove everything they believe, Aristotle realized that you can demand proof for the premises every time proof is offered, and impose an infinite regress. Some things are so basic as not to require proof.
XVI. The Law of Non-Contradiction
• An example would be the law of noncontradiction in logic, the claim that a statement and its contradictory cannot both be true. The trouble here is that any argument for the law of noncontradiction is going to assume the law of noncontradiction, and thereby be open to charge of being a circular argument. However, if someone doesn’t believe in the law of noncon, Aristotle will ask “Are you really saying that?” If the person says they are making a statement, then Aristotle will say that the person has implicitly accepted the law of non-contradiction. If the person says “No, I’m not really saying that,” then Aristotle says “Well, if you aren’t really saying anything, then I really have nothing to respond to,” and treat the person as a cabbage.
3 comments:
Very lucid and helpful class notes. Your students must enjoy your class!
(just in case you didn't notice -- a ticky-tacky point: second bullet under section XIII: I think you wanted to say, "then the conclusion is guaranteed to be true" (not "and the conclusion is guaranteed to be true")
Victor,
If it is true that you are offering this as your lecture notes to a class, I have some fundamental suggestions that will aid you in the teaching of your students. I know these notes are rather sparse, yet judging what I can from them; I am concerned that you are going to be misinforming not only "exapologist," but many of your pupils.
”While Plato’s philosophy is idealistic, inspiring, otherworldly and perfectionist, Aristotle’s is realistic, scientific, this-worldly and pragmatic.”
You, like so many others, are confusing Platonism with the Neo-Platonist distortions of Plotinus.
To call Aristotle a “common-sense” philosopher is rather contentious; not only does the term “common-sense” have a distinct (and controversial) meaning in the history of philosophy, but it appears that you are using it here too broadly, perhaps meaning only that *you* consider Aristotle to be more coherent than other philosophers. I’d excise this term, as it appears to aid no other purpose than to propound how you feel about Aristotle, rather than what he said.
Concerning who is “other-worldly” and “this-wordly,” your distinction is false; it is Plato is more of a monist than Aristotle; as such, Aristotle, not Plato, who divides the world into realms. Aristotle, not Plato, makes metaphysical distinctions between “the otherworldly and perfectionist.” Although the Forms are perfect according to Plato, Aristotle’s celestial, “Super-Lunar” world is the supernatural world; as such, it is “perfect” because the “Super-Lunar” world operates according to the perfections of circularity, that is, perfectly circular orbits. The “Sub-Lunar” world concerned the natural world. For Plato, his Parmenidean and Pythagoran influences are clear, such that his monistic ontology stems from a principle that includes all being, unhypothetically. Pace Augustine, Alexander, Plotinus, et al., Platonism makes no room for a supernatural realm; for Plato, even the gods were part of the One.
Concerning abstract objects, Aristotle never rejected the Forms; it is he, not Plato, deviated from the Monism of his teacher; refer to Metaphysics Beta (B) (995a24-1003a2, cf. 1002b14 and L. Gerson 2005). In fact, throughout Beta (B), Aristotle thoroughly defends the existence and provides an ontology of first principles (arche) in such a way, that the Neo-Platonists would ally more with Aristotle’s conceptions of mathematical objects than with what Plato actually said.
Plato is no less scientific than Aristotle (cf. A. Gregory 2001, D. Nails 1986). For the sake of you and your students, leave this point out. As well, Plato is not an idealist, in any sense. Once again, you are adopting Plotinus over Plato; confer with Parmenides 129a, 130a-131a and with Phaedo 65d-e, among others. Feyerabend teaches his Philosophy of Science course only using the dialogues. For Plato, the Forms, chairs, soldiers, numbers, and any other abstracta are all part of an ontological unity.
Futhermore, Sophists weren’t necessarily the “deniers of knowledge,” as much as they were, such as Isocrates, those who claimed to be the “havers of knowledge” and teachers of rhetoric.
Your divisions of the Categories (bk. 1a1-15b33) are accurate, yet Aristotle clearly abandons them up to and after the Prior Analytics (24a10-70b38), and never refers to them in the Metaphysics.
Concerning section “XV. First Principles,” you are likely referring to Aristotle’s comment on logical axioms in Metaphysics Gamma (Γ) at 1011a1-13. You say, “Aristotle maintained that there were certain fundamental principles in every discipline […] Aristotle realized that you can demand proof for the premises every time proof is offered, and impose an infinite regress. Some things are so basic as not to require proof.”
Sadly, this is wrong. Throughout Metaphysics Beta (B) in his discussion of axioms (cf. 997b3-9998a19) and the law of non-contradiction, throughout Gamma, Aristotle clearly makes the distinction between self-evident truths and merely presupposing the truth of some statements arbitrarily. The latter cannot be denied; the former is merely stipulation. In the Posterior Analytics, Aristotle repeatedly notes that if some statements can be merely granted, without self-evidence, then any notion of major premises, minor premises, logical consequence, etc. goes out the window.
“For Plato there can be no science (rational discourse) of particular things. For Aristotle there can be, in fact knowledge begins with the study of particular things.”
You should be more cautious with your assertions. That Aristotle granted that knowledge of particulars is prior to knowledge of universals is controversial throughout the history of philosophy. There is no consensus that he maintained the former over the latter, or vice versa (cf. A. Code 1976 and C. Long 1999).
I have to get going here, but your comment on the principle of non-contradiction (XVI) is confusing:
“If the person says they are making a statement, then Aristotle will say that the person has implicitly accepted the law of non-contradiction […].”
I don’t know where Aristotle argued for that or where you got that notion; similarly for section V.
All in all, you should be more charitable to the myriad of opposing viewpoints and arguments. As such, you should make clear what is controversial among scholars and where objections are, rather than making such confident assertions. Few, if any, of the points on your outline, even concerning Aristotle’s logic, are generally agreed upon. Caricature and lack of emphasis can leave the minds of students to gross misconceptions. Concerning what you say about Plato; scholars would be spinning in their “office chairs” if they read your notes.
Sapere aude,
T.A.
I am not, of course, a Plato or Aristotle scholar, and I have to rely on the text that I use and other material that I can come up with to help get the ideas across. I happen to use William Lawhead's the Voyage of Discovery. Of course, there is a large industry of scholarship about what these thinkers have to say, and lots of non-standard interpretations of these people get advanced. Sometimes I think these "interpretations" are just invented by people trying to publish papers and advance reputations. But for the purpose of explaining fundamental philosophical ideas to the introductory student, I don't think I should have to apologize for accepting some standard textbook interpretations. I sometimes do mention that all these philosophers generate a huge amount of debate about what they actually meant.
These things always make it frustrating to teachers of introductory philosophy. You have to oversimplify some things that might have to be corrected if students go on to higher levels of study.
I have serious doubts about the interpretation of Plato that you present.
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