Combining Texts

All the ideas for '', 'On the Principles of Indiscernibles' and 'Rationality'

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7 ideas

5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt]
     Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation.
     From: Ian Rumfitt ("Yes" and "No" [2000], II)
     A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]
     Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table.
     From: Ian Rumfitt ("Yes" and "No" [2000])
     A reaction: This is the standard view which Rumfitt sets out to challenge.
The sense of a connective comes from primitively obvious rules of inference [Rumfitt]
     Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious.
     From: Ian Rumfitt ("Yes" and "No" [2000], III)
     A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value.
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
The ancient Memorists said virtually all types of thinking could be done simply by memory [Sorabji]
     Full Idea: The ancient medical Memorists said that ordinary thinking, inferring, reflecting, believing, assuming, examining, generalising and knowing can all be done simply on the basis of memory.
     From: Richard Sorabji (Rationality [1996], 'Inference')
     A reaction: The think there is a plausible theory that all neurons do is remember, and are mainly distinguished by the duration of their memories. We might explain these modes of thinking in terms of various combinations of the fast and the slow.
Stoics say true memory needs reflection and assent, but animals only have perceptual recognition [Sorabji]
     Full Idea: Stoics say memory proper involves reflection and assent. Animal memory, by contrast, is not memory proper, but mere perceptual recognition. The horse remembers the road when he is on it, but not when he is in the stable.
     From: Richard Sorabji (Rationality [1996], 'Other')
     A reaction: An interesting distinction. Do I remember something if I can never recall it, and yet recognise it when it reappears, such as a person I knew long ago? 'Memory' is ambiguous, between lodged in the mind, and recallable. Unfair to horses, this.
19. Language / F. Communication / 3. Denial
We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt]
     Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A.
     From: Ian Rumfitt ("Yes" and "No" [2000], IV)
     A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role).
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
The concept of an existing thing must contain more than the concept of a non-existing thing [Leibniz]
     Full Idea: There must be more in the concept of a thing which exists than in that of one which does not exist.
     From: Gottfried Leibniz (On the Principles of Indiscernibles [1696], p.134)