11 ideas
| 4037 | Ockham's Razor is the principle that we need reasons to believe in entities [Mellor/Oliver] |
| Full Idea: Ockham's Razor is the principle that we need reasons to believe in entities. | |
| From: DH Mellor / A Oliver (Introduction to 'Properties' [1997], §9) | |
| A reaction: This presumably follows from an assumption that all beliefs need reasons, but is that the case? The Principle of Sufficient Reason precedes Ockham's Razor. |
| 13342 | Carnap defined consequence by contradiction, but this is unintuitive and changes with substitution [Tarski on Carnap] |
| Full Idea: Carnap proposed to define consequence as 'sentence X follows from the sentences K iff the sentences K and the negation of X are contradictory', but 1) this is intuitively impossible, and 2) consequence would be changed by substituting objects. | |
| From: comment on Rudolph Carnap (The Logical Syntax of Language [1934], p.88-) by Alfred Tarski - The Concept of Logical Consequence p.414 | |
| A reaction: This seems to be the first step in the ongoing explicit discussion of the nature of logical consequence, which is now seen by many as the central concept of logic. Tarski brings his new tool of 'satisfaction' to bear. |
| 13251 | Each person is free to build their own logic, just by specifying a syntax [Carnap] |
| Full Idea: In logic, there are no morals. Everyone is at liberty to build his own logic, i.e. his own form of language. All that is required is that he must state his methods clearly, and give syntactical rules instead of philosophical arguments. | |
| From: Rudolph Carnap (The Logical Syntax of Language [1934], §17), quoted by JC Beall / G Restall - Logical Pluralism 7.3 | |
| A reaction: This is understandable, but strikes me as close to daft relativism. If I specify a silly logic, I presume its silliness will be obvious. By what criteria? I say the world dictates the true logic, but this is a minority view. |
| 8568 | A property is merely a constituent of laws of nature; temperature is just part of thermodynamics [Mellor] |
| Full Idea: Being a constituent of probabilistic laws of nature is all there is to being a property. There is no more to temperature than the thermodynamics and other laws they occur in. | |
| From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
| A reaction: How could thermodynamics be worked out without a prior concept of temperature? I think it is at least plausible to deny that there are any 'laws' of nature. But even Quine can't deny that some things are too hot to touch. |
| 4027 | Properties are respects in which particular objects may be alike or differ [Mellor/Oliver] |
| Full Idea: Properties are respects in which particular objects may be alike or differ. | |
| From: DH Mellor / A Oliver (Introduction to 'Properties' [1997], §1) | |
| A reaction: Note that this definition does not mention a causal role for properties. |
| 8564 | There is obviously a possible predicate for every property [Mellor] |
| Full Idea: To every property there obviously corresponds a possible predicate applying to all and only those particulars with that property. | |
| From: D.H. Mellor (Properties and Predicates [1991], 'Intro') | |
| A reaction: This doesn't strike me as at all obvious. If nature dictates the properties, there may be vastly more than any human language could cope with. It is daft to say that a property can only exist if humanity can come up with a predicate for it. |
| 4029 | Nominalists ask why we should postulate properties at all [Mellor/Oliver] |
| Full Idea: Nominalists ask why we should postulate properties at all. | |
| From: DH Mellor / A Oliver (Introduction to 'Properties' [1997], §3) | |
| A reaction: Objects might be grasped without language, but events cannot be understood, and explanations of events seem inconceivable without properties (implying that they are essentially causal). |
| 8566 | We need universals for causation and laws of nature; the latter give them their identity [Mellor] |
| Full Idea: I take the main reason for believing in contingent universals to be the roles they play in causation and in laws of nature, and those laws are what I take to give those universals their identity. | |
| From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
| A reaction: He agrees with Armstrong. Sounds a bit circular - laws are built on universals, and universals are identified by laws. It resembles a functionalist account of mental events. I think it is wrong. A different account of laws will be needed... |
| 8565 | If properties were just the meanings of predicates, they couldn't give predicates their meaning [Mellor] |
| Full Idea: One reason for denying that properties just are the meanings of our predicates is that, if they were, they could not give our predicates their meanings. | |
| From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
| A reaction: Neither way round sounds quite right to me. Predicate nominalism is wrong, but what is meant by a property 'giving' a predicate its meaning? It doesn't seem to allow room for error in our attempts to name the properties. |
| 4039 | Abstractions lack causes, effects and spatio-temporal locations [Mellor/Oliver] |
| Full Idea: Abstract entities (such as sets) are usually understood as lacking causes, effects, and spatio-temporal location. | |
| From: DH Mellor / A Oliver (Introduction to 'Properties' [1997], §10) | |
| A reaction: This seems to beg some questions. Has the ideal of 'honour' never caused anything? Young men dream of pure velocity. |
| 8567 | Singular causation requires causes to raise the physical probability of their effects [Mellor] |
| Full Idea: Singular causation entails physical probabilities or chances. ...Causal laws require causes to raise their effects' chances, as when fires have a greater chance of occurring when explosions do. | |
| From: D.H. Mellor (Properties and Predicates [1991], 'Props') | |
| A reaction: It seems fairly obvious that a probability can be increased without actually causing something. Just after a harmless explosion is a good moment for arsonists, especially if Mellor will be the investigating officer. |