Combining Texts

All the ideas for 'What is so bad about Contradictions?', 'Comments on a Certain Broadsheet' and 'Philosophy of Arithmetic'

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11 ideas

2. Reason / B. Laws of Thought / 3. Non-Contradiction

9123	Someone standing in a doorway seems to be both in and not-in the room [Priest,G, by Sorensen]
	Full Idea: Priest says there is room for contradictions. He gives the example of someone in a doorway; is he in or out of the room. Given that in and out are mutually exclusive and exhaustive, and neither is the default, he seems to be both in and not in.
	From: report of Graham Priest (What is so bad about Contradictions? [1998]) by Roy Sorensen - Vagueness and Contradiction 4.3
	A reaction: Priest is a clever lad, but I don't think I can go with this. It just seems to be an equivocation on the word 'in' when applied to rooms. First tell me the criteria for being 'in' a room. What is the proposition expressed in 'he is in the room'?

6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / l. Zero

9837	0 is not a number, as it answers 'how many?' negatively [Husserl, by Dummett]
	Full Idea: Husserl contends that 0 is not a number, on the grounds that 'nought' is a negative answer to the question 'how many?'.
	From: report of Edmund Husserl (Philosophy of Arithmetic [1894], p.144) by Michael Dummett - Frege philosophy of mathematics Ch.8
	A reaction: I seem to be in a tiny minority in thinking that Husserl may have a good point. One apple is different from one orange, but no apples are the same as no oranges. That makes 0 a very peculiar number. See Idea 9838.

6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units

9576	Multiplicity in general is just one and one and one, etc. [Husserl]
	Full Idea: Multiplicity in general is no more than something and something and something, etc.; ..or more briefly, one and one and one, etc.
	From: Edmund Husserl (Philosophy of Arithmetic [1894], p.85), quoted by Gottlob Frege - Review of Husserl's 'Phil of Arithmetic'
	A reaction: Frege goes on to attack this idea fairly convincingly. It seems obvious that it is hard to say that you have seventeen items, if the only numberical concept in your possession is 'one'. How would you distinguish 17 from 16? What makes the ones 'multiple'?

6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation

17444	Husserl said counting is more basic than Frege's one-one correspondence [Husserl, by Heck]
	Full Idea: Husserl famously argued that one should not explain number in terms of equinumerosity (or one-one correspondence), but should explain equinumerosity in terms of sameness of number, which should be characterised in terms of counting.
	From: report of Edmund Husserl (Philosophy of Arithmetic [1894]) by Richard G. Heck - Cardinality, Counting and Equinumerosity 3
	A reaction: [Heck admits he hasn't read the Husserl] I'm very sympathetic to Husserl, though nearly all modern thinking favours Frege. Counting connects numbers to their roots in the world. Mathematicians seem oblivious of such things.

12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities

2602	What experience could prove 'If a=c and b=c then a=b'? [Descartes]
	Full Idea: Please tell me what the corporeal motion is that is capable of forming some common notion to the effect that 'things which are equal to a third thing are equal to each other'.
	From: René Descartes (Comments on a Certain Broadsheet [1644], p.366)

15. Nature of Minds / C. Capacities of Minds / 3. Abstraction by mind

9575	Husserl identifies a positive mental act of unification, and a negative mental act for differences [Husserl, by Frege]
	Full Idea: Husserl identifies a 'unitary mental act' where several contents are connected or related to one another, and also a difference-relation where two contents are related to one another by a negative judgement.
	From: report of Edmund Husserl (Philosophy of Arithmetic [1894], p.73-74) by Gottlob Frege - Review of Husserl's 'Phil of Arithmetic' p.322
	A reaction: Frege is setting this up ready for a fairly vicious attack. Where Hume has a faculty for spotting resemblances, it is not implausible that we should also be hard-wired to spot differences. 'You look different; have you changed your hair style?'

18. Thought / D. Concepts / 2. Origin of Concepts / c. Nativist concepts

2600	The mind's innate ideas are part of its capacity for thought [Descartes]
	Full Idea: I have never written or taken the view that the mind requires innate ideas which are something distinct from its own faculty of thinking.
	From: René Descartes (Comments on a Certain Broadsheet [1644], p.365)

2601	Qualia must be innate, because physical motions do not contain them [Descartes]
	Full Idea: The ideas of pains, colours, sounds etc. must be all the more innate if, on the occasion of certain corporeal motions, our mind is to be capable of representing them to itself, for there is no similarity between these ideas and the corporeal motions.
	From: René Descartes (Comments on a Certain Broadsheet [1644], p.365)
	A reaction: Simple and brilliant! We know perfectly well that there is no redness zooming through the air from a tomato (or the air would be pink!). Redness occurs when the light arrives, so we add the redness, so it is innate.

18. Thought / D. Concepts / 4. Structure of Concepts / b. Analysis of concepts

21214	We clarify concepts (e.g. numbers) by determining their psychological origin [Husserl, by Velarde-Mayol]
	Full Idea: Husserl said that the clarification of any concept is made by determining its psychological origin. He is concerned with the psychological origins of the operation of calculating cardinal numbers.
	From: report of Edmund Husserl (Philosophy of Arithmetic [1894]) by Victor Velarde-Mayol - On Husserl 2.2
	A reaction: This may not be the same as the 'psychologism' that Frege so despised, because Husserl is offering a clarification, rather than the intrinsic nature of number concepts. It is not a theory of the origin of numbers.

18. Thought / E. Abstraction / 8. Abstractionism Critique

9819	Psychologism blunders in focusing on concept-formation instead of delineating the concepts [Dummett on Husserl]
	Full Idea: Husserl substitutes his account of the process of concept-formation for a delineation of the concept. It is above all in making this substitution that psychologism is objectionable (and Frege opposed it so vehemently).
	From: comment on Edmund Husserl (Philosophy of Arithmetic [1894]) by Michael Dummett - Frege philosophy of mathematics Ch.2
	A reaction: While this is a powerful point which is a modern orthodoxy, it hardly excludes a study of concept-formation from being of great interest for other reasons. It may not appeal to logicians, but it is crucial part of the metaphysics of nature.

9851	Husserl wanted to keep a shadowy remnant of abstracted objects, to correlate them [Dummett on Husserl]
	Full Idea: Husserl saw that abstracted units, though featureless, must in some way retain their distinctness, some shadowy remnant of their objects. So he wanted to correlate like-numbered sets, not just register their identity, but then abstractionism fails.
	From: comment on Edmund Husserl (Philosophy of Arithmetic [1894]) by Michael Dummett - Frege philosophy of mathematics Ch.12
	A reaction: Abstractionism is held to be between the devil and the deep blue sea, of depending on units which are identifiable, when they are defined as devoid of all individuality. We seem forced to say that the only distinction between them is countability.