Combining Philosophers

All the ideas for Douglas Lackey, Godfrey Vesey and Francis of Marchia

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4 ideas

5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / b. Cantor's paradox
21554 Sets always exceed terms, so all the sets must exceed all the sets [Lackey]
     Full Idea: Cantor proved that the number of sets in a collection of terms is larger than the number of terms. Hence Cantor's Paradox says the number of sets in the collection of all sets must be larger than the number of sets in the collection of all sets.
     From: Douglas Lackey (Intros to Russell's 'Essays in Analysis' [1973], p.127)
     A reaction: The sets must count as terms in the next iteration, but that is a normal application of the Power Set axiom.
5. Theory of Logic / L. Paradox / 5. Paradoxes in Set Theory / c. Burali-Forti's paradox
21553 It seems that the ordinal number of all the ordinals must be bigger than itself [Lackey]
     Full Idea: The ordinal series is well-ordered and thus has an ordinal number, and a series of ordinals to a given ordinal exceeds that ordinal by 1. So the series of all ordinals has an ordinal number that exceeds its own ordinal number by 1.
     From: Douglas Lackey (Intros to Russell's 'Essays in Analysis' [1973], p.127)
     A reaction: Formulated by Burali-Forti in 1897.
9. Objects / D. Essence of Objects / 13. Nominal Essence
16627 If you remove the accidents from a horse and a lion, the intellect can't tell them apart [Francis of Marchia]
     Full Idea: Let all accidents be removed from a lion and a horse. Nothing remains in the intellect to distinguish them. We distinguish a lion and a horse only by analogy to the accidents proper to each. The intellect does not have an essential concept of either one.
     From: Francis of Marchia (Commentary on Sentences [1330], I.3.1), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 07.3
     A reaction: What a very nice thought experiment, and very convincing about how the mind perceives such things. But we don't believe horse and lion just consists of the surface properties of them which we experience.
12. Knowledge Sources / B. Perception / 4. Sense Data / b. Nature of sense-data
6457 Sensations are mental, but sense-data could be mind-independent [Vesey]
     Full Idea: Whereas a sensation is by definition mental, a sense-datum might be mind-independent.
     From: Godfrey Vesey (Collins Dictionary of Philosophy [1990], p.266)
     A reaction: This seems to be what Russell is getting at in 1912, as he clearly separates sense-data from sensations. Discussions of sense-data always assume they are mental, which may make them redundant - but so might making them physical.