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. |
| 19400 | Possibles demand existence, so as many of them as possible must actually exist [Leibniz] |
| Full Idea: From the conflict of all the possibles demanding existence, this at once follows, that there exists that series of things by which as many of them as possible exist. | |
| From: Gottfried Leibniz (Exigency to Exist in Essences [1690], p.91) | |
| A reaction: I'm in tune with a lot of Leibniz, but my head swims with this one. He seems to be a Lewisian about possible worlds - that they are concrete existing entities (with appetites!). Could Lewis include Leibniz's idea in his system? |
| 19401 | God's sufficient reason for choosing reality is in the fitness or perfection of possibilities [Leibniz] |
| Full Idea: The sufficient reason for God's choice can be found only in the fitness (convenance) or in the degree of perfection that the several worlds possess. | |
| From: Gottfried Leibniz (Exigency to Exist in Essences [1690], p.92) | |
| A reaction: The 'fitness' of a world and its 'perfection' seem very different things. A piece of a jigsaw can have wonderful fitness, without perfection. Occasionally you get that sinking feeling with metaphysicians that they just make it up. |
| 10467 | Individuals consist of 'compresent' tropes [Bacon,John] |
| Full Idea: 'Qualitons' or 'relatons' (quality and relation tropes) are held to belong to the same individual if they are all 'compresent' with one another. | |
| From: John Bacon (Tropes [2008], §4) | |
| A reaction: There is a perennial problem with bundles - how to distinguish accidental compresence (like people in a lift) from united compresence (like people who make a family). |
| 10464 | A trope is a bit of a property or relation (not an exemplification or a quality) [Bacon,John] |
| Full Idea: A trope is an instance or bit (not an exemplification) of a property or a relation. Bill Clinton's eloquence is not his participating in the universal eloquence, or the peculiar quality of his eloquence, but his bit, and his alone, of eloquence. | |
| From: John Bacon (Tropes [2008], Intro) | |
| A reaction: If we have identified something as a 'bit' of something, we can ask whether that bit is atomic, or divisible into something else, and we can ask what are the qualities and properties and powers of this bit, we seems to defeat the object. |
| 10465 | Trope theory is ontologically parsimonious, with possibly only one-category [Bacon,John] |
| Full Idea: A major attraction of tropism has been its promise of parsimony; some adherents (such as Campbell) go so far as to proclaim a one-category ontology. | |
| From: John Bacon (Tropes [2008], §2) | |
| A reaction: This seems to go against the folk idiom which suggests that it is things which have properties, rather than properties ruling to roost. Maybe if one identified tropes with processes, the theory could be brought more into line with modern physics? |
| 19402 | The actual universe is the richest composite of what is possible [Leibniz] |
| Full Idea: The actual universe is the collection of the possibles which forms the richest composite. | |
| From: Gottfried Leibniz (Exigency to Exist in Essences [1690], p.92) | |
| A reaction: 'Richest' for Leibniz means a maximum combination of existence, order and variety. It's rather like picking the best starting team from a squad of footballers. |
| 10466 | Maybe possible worlds are just sets of possible tropes [Bacon,John] |
| Full Idea: Meinongian tropism has the advantage that possible worlds might be thought of as sets of 'qualitons' and 'relatons' (quality and relational tropes). | |
| From: John Bacon (Tropes [2008], §3) | |
| A reaction: You are still left with 'possible' to explain, and I'm not sure that anything is explain here. If the actual world is sets of tropes, then possible worlds would also have to be, I suppose. |
| 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). |