Combining Texts

Ideas for 'Metaphysics', 'Ecce Homo' and 'On the Plurality of Worlds'

unexpand these ideas     |    start again     |     choose another area for these texts

display all the ideas for this combination of texts

17 ideas

18. Thought / A. Modes of Thought / 5. Rationality / b. Human rationality
23311 Aristotle sees reason as much more specific than our more everyday concept of it [Aristotle, by Frede,M]
     Full Idea: It seems that Aristotle does not associate reason primarily with ordinary, everyday thought and reasoning, as we do, but with a much more specific function of reason.
     From: report of Aristotle (Metaphysics [c.324 BCE], 980b) by Michael Frede - Aristotle's Rationalism p.163
     A reaction: Although Aristotle is naturalistic, he is also a bit of a dualist, and so is less keen than I am to connect human reason with sensible behaviour in animals.
18. Thought / A. Modes of Thought / 5. Rationality / c. Animal rationality
23310 Animals live by sensations, and some have good memories, but they don't connect experiences [Aristotle]
     Full Idea: By nature animals are born with the faculty of sensation, and from sensation memory is produced in some of them, though not in others; therefore the former are more intelligent. …Animals live by appearances and memories, with little connected experience.
     From: Aristotle (Metaphysics [c.324 BCE], 980a28-)
     A reaction: I assume that larger animals make judgements, which have to rely on previous experiences, so I think he underestimates the cleverest animals. We now know about Caledonian Crows, which amaze us, and would have amazed Aristotle.
18. Thought / B. Mechanics of Thought / 5. Mental Files
11245 Many memories make up a single experience [Aristotle]
     Full Idea: Many recollections of the same thing perform the function of a single experience.
     From: Aristotle (Metaphysics [c.324 BCE], 0980b28)
     A reaction: This beautifully simple remark seems to me to be extremely important if we are going to understand the nature of thought. Personally I think it endorses the 'database' view of how the mind works (as a set of labelled 'files'). See Fodor's 'LOT2'.
18. Thought / D. Concepts / 4. Structure of Concepts / i. Conceptual priority
10954 It is unclear whether acute angles are prior to right angles, or fingers to men [Aristotle]
     Full Idea: Suppose parts are prior to the whole - then, since the acute angle is a part of the right angle, and a finger is part of an animal, this would mean the acute angle and the finger were prior, but received opinion says otherwise.
     From: Aristotle (Metaphysics [c.324 BCE], 1034b24)
18. Thought / E. Abstraction / 1. Abstract Thought
8901 Abstraction is usually explained either by example, or conflation, or abstraction, or negatively [Lewis]
     Full Idea: Abstraction is usually explained in one of four ways: the Way of Example (cf. donkeys and numbers), the Way of Conflation (same as sets), the Negative Way (non-spatial and non-causal) or the Way of Abstraction (incomplete descriptions).
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: [Compressed; a footnote dismisses Dummett's fifth way] Example has blurred boundaries, and explains nothing. Gerrymandered sets don't produce concepts. Negative accounts explain nothing. So it's the Way of Abstraction!
18. Thought / E. Abstraction / 3. Abstracta by Ignoring
9792 Mathematicians study quantity and continuity, and remove the perceptible features of things [Aristotle]
     Full Idea: The mathematician conducts a study into things in abstraction (after the removal of all perceptible features, such as weight and hardness, leaving only quantity and continuity).
     From: Aristotle (Metaphysics [c.324 BCE], 1061a26)
     A reaction: Frege complained that there is nothing left if you remove the perceptible features, but clearly Aristotle is not an empiricist in this passage, and it is doubtful if even Mill can be totally empirical in his account. We have relations of ideas.
9077 Mathematicians suppose inseparable aspects to be separable, and study them in isolation [Aristotle]
     Full Idea: Study things as mathematicians do. Suppose what is not separable to be separable. A man qua man is an indivisible unity, so the arithmetician supposes a man to be an indivisible unity, and investigates the accidental features of man qua indivisible.
     From: Aristotle (Metaphysics [c.324 BCE], 1078a19)
     A reaction: This is the abstractionist view of mathematics. Qua indivisible, a man will have the same properties as a toothbrush. Aristotle clearly intends the method for scientists as well. It strikes me as common sense, but there is a lot of modern caution.
8904 The Way of Abstraction says an incomplete description of a concrete entity is the complete abstraction [Lewis]
     Full Idea: The Way of Abstraction says abstract entities are abstractions from concrete entities; they result from somehow subtracting specificity, so that an incomplete description of the original concrete entity is a complete description of the abstraction.
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: Defined like this, it rather looks as if abstractions would be entirely verbal - which may well be the correct situation, except that higher animals seem capable of minimal levels of abstraction. This Way is denigrated by Frege and Geach.
18. Thought / E. Abstraction / 4. Abstracta by Example
8938 The Way of Example compares donkeys and numbers, but what is the difference, and what are numbers? [Lewis]
     Full Idea: The Way of Example says concrete entities are things like donkeys and puddles, but abstract entities are things like numbers. That gives us little guidance. There are no uncontroversial accounts of numbers, and donkeys and number differ in too many ways.
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: That demolishes that fairly swiftly. It may be unfair to demand an agreed account of numbers, but the respect(s) in which donkeys and numbers differ needs to be spelled out before anything useful has been said.
18. Thought / E. Abstraction / 6. Abstracta by Conflation
8903 Abstracta can be causal: sets can be causes or effects; there can be universal effects; events may be sets [Lewis]
     Full Idea: Is it true that sets or universals cannot enter into causal interaction? Why can't we say that a set of things causes something, or something causes a set of effects? Or positive charge has characteristic effects? Or an event is a sort of set?
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: This idea, and 8902, form a devastating critique of attempts to define abstraction in a purely negative way, as non-spatial and non-causal. Only a drastic revision of widely held views about sets, universals and events could save that account.
8902 If abstractions are non-spatial, then both sets and universals seem to have locations [Lewis]
     Full Idea: If abstract entities are not located, then a set of things does seem to have a location, though perhaps a divided one; and universals, if they are wholly present in each particular, are where their instances are, so negation can't define abstraction.
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: He admits that non-spatial accounts of sets and universals are possible, but the jury is out on both of them, and more cautious theories, even if they are realist, will give them both locations. A good argument.
8905 If universals or tropes are parts of things, then abstraction picks out those parts [Lewis]
     Full Idea: A theory of non-spatiotemporal parts of things, whether recurring universals or non-recurring tropes, makes good sense of some abstractions. Unit negative charge is a universal common to particles, and an abstraction by being part of them.
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: He cautiously refers to 'some' abstractions. It is one of Donald Williams's proud boasts concerning his trope theory that it will handle this problem well. I'm not sure that we should be saying that abstractions are actually concrete bits of things.
8906 If we can abstract the extrinsic relations and features of objects, abstraction isn't universals or tropes [Lewis]
     Full Idea: Why can't we abstract a highly extrinsic aspect of something, say its surname, or its spatiotemporal location, or its role in a causal network, or its role in some body of theory? But these are unsuitable candidates for being genuine universals or tropes.
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: (This is a criticism of the proposal in Idea 8905) Obviously we can abstract such things. In particular the role in a causal network is a function, which is a central example of an abstract idea. Russell keeps reminding us that relations are universals.
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
8907 The abstract direction of a line is the equivalence class of it and all lines parallel to it [Lewis]
     Full Idea: We can abstract the direction of a line by taking the direction as the equivalence class of that line and all lines parallel to it. There is no subtraction of detail, but a multiplication of it; by swamping it, the specifics of the original line get lost.
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: You can ask how wide a line is, but not how wide a direction is, so a detail IS being subtracted. I don't see how you can define the concept of a banana by just saying it is 'every object which is equivalent to a banana'. 'Parallel' is an abstraction.
8908 For most sets, the concept of equivalence is too artificial to explain abstraction [Lewis]
     Full Idea: Most sets cannot be regarded as abstractions by equivalence: most sets are equivalence classes only under thoroughly artificial equivalence. (And the empty set is not an equivalence class at all).
     From: David Lewis (On the Plurality of Worlds [1986], 1.7)
     A reaction: [Recorded for further investigation..] My intuitions certainly cry out against such a thin logical notion giving a decent explanation of such a rich activity as abstraction.
18. Thought / E. Abstraction / 8. Abstractionism Critique
16289 We can't account for an abstraction as 'from' something if the something doesn't exist [Lewis]
     Full Idea: We cannot really be talking about the things whence an abstraction-like entity is abstracted if there are no such things.
     From: David Lewis (On the Plurality of Worlds [1986], 3.3)
     A reaction: Sounds like a killer blow, but I don't think so. I can't think of a concept which doesn't have a possible basis in reality, assuming that it might be a complex assemblage of abstracted components.
9075 If health happened to be white, the science of health would not study whiteness [Aristotle]
     Full Idea: If we have a science of the healthy, and the healthy happens to be white, the science of the healthy does not deal with the white.
     From: Aristotle (Metaphysics [c.324 BCE], 1077b30)
     A reaction: Given this point, we certainly cannot think of Aristotle as believing in simple abstractionism. The problem of the coextension of renates and cordates looms here (Idea 7317). 'Relevant' similarities require extensive cross-referencing.