11 ideas
11211 | 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. |
11210 | 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. |
11212 | 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. |
3913 | Maybe imagination is the source of a priori justification [Casullo] |
Full Idea: Some maintain that experiments in imagination are the source of a priori justification. | |
From: Albert Casullo (A priori/A posteriori [1992], p.1) | |
A reaction: What else could assessments of possibility and necessity be based on except imagination? |
5952 | Rather than being the whole soul, maybe I am its chief part? [Plutarch] |
Full Idea: Is each of us not the soul, but the chief part of the soul, by which we think and reason and act, all the other parts of soul as well as of body being mere instruments of its power? | |
From: Plutarch (74: Reply to Colotes [c.85], §1119) | |
A reaction: Socrates is associated with the idea that I am my whole soul (Idea 1650). Plutarch represents an interesting development, which may lead both to the Christian 'soul' and to the Cartesian 'ego'. I think Plutarch is right, but what is the 'soul'? |
5951 | If atoms have no qualities, they cannot possibly produce a mind [Plutarch] |
Full Idea: Perception, mind, intelligence and thought cannot so much as be conceived, even with the best will, as arising among void and atoms, things which taken separately have no quality. | |
From: Plutarch (74: Reply to Colotes [c.85], §1112) | |
A reaction: A nice articulation of the intuition of all anti-physicalists. Plutarch would have to rethink his position carefully if he learned of the sheer number of connections in the brain, and of the theory of natural selection. His challenge remains, though. |
11214 | 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). |
20796 | Action needs an affinity for a presentation, and an impulse toward the affinity [Plutarch] |
Full Idea: The sceptics say there are three movements of the soul: presentation, impulse and assent. …And action requires two things: a presentation of something to which one has an affinity, and an impulse toward what is presented as an object of affinity. | |
From: Plutarch (74: Reply to Colotes [c.85], 1122c) | |
A reaction: Not much reasoning involved in this account, which the sceptics say is compatible with suspension of judgement. |
5948 | The good life involves social participation, loyalty, temperance and honesty [Plutarch] |
Full Idea: To live the good life is to live a life of participation in society, of loyalty to friends, of temperance and honest dealing. | |
From: Plutarch (74: Reply to Colotes [c.85], §1108) | |
A reaction: 'Participation in society' is the interesting one. This might translate as 'doing your duty', or as 'leading a well-rounded life'. Solitude is wrong if you are indebted to others, and it is unhealthy if you are not. Is solitude really immoral, though? |
5950 | If only atoms exist, how do qualities arise when the atoms come together? [Plutarch] |
Full Idea: If you accept atomism, you must show how bodies without quality have given rise to qualities of every kind by the mere fact of coming together. For example, how has the quality called 'hot' been imposed on the atoms? | |
From: Plutarch (74: Reply to Colotes [c.85], §1111) | |
A reaction: This argument is still significant in current philosophy of mind. If temperature is 'mean kinetic energy', you are left wondering where the energy came from, and why minds experience the heat. This is the 'Hard Question'. |
5955 | No one will ever find a city that lacks religious practices [Plutarch] |
Full Idea: A city without holy places and gods, without any observance of prayers, oaths, oracles, sacrifices for blessings received or rites to avert evils, no traveller has ever seen or will ever see. | |
From: Plutarch (74: Reply to Colotes [c.85], §1125) | |
A reaction: The nearest you might get would be Soviet Moscow, but in 1973 I saw a man there jeering at a woman who was kneeling in the street outside a closed church. Plutarch would be stunned at the decline in religious practices in modern Europe. |