39 ideas
| 3879 | Philosophy aims to provide a theory of everything [Scruton] |
| Full Idea: Philosophy studies everything: it tries to provide a theory of the whole of things. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 1.2) | |
| A reaction: Good, but you can't avoid value-judgements about which things are important; philosophers place more value on moral theories than on theories about glacier movement. There is a tension in philosophy between human and eternal concerns. |
| 3891 | If p entails q, then p is sufficient for q, and q is necessary for p [Scruton] |
| Full Idea: If p entails q, then p is sufficient for q, and q is necessary for p. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 15.7) |
| 3894 | We may define 'good' correctly, but then ask whether the application of the definition is good [Scruton] |
| Full Idea: The 'open question' argument is clearly invalid. A question remains open just so long as our ignorance permits. …It may be an open question whether promoting happiness is good, even though this is what 'good' means. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 20.1) | |
| A reaction: A nice objection. Like small children, we can keep asking questions forever. Whether there is a question to be asked about a thing is not a property of that thing, but of us who ask it. |
| 3883 | A true proposition is consistent with every other true proposition [Scruton] |
| Full Idea: A true proposition is consistent with every other true proposition: no truth is contradicted by another. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 9.1) | |
| A reaction: Interesting. It resembles the rule that if you always tell the truth you don't need to remember what you said. Close to the heart of the concept of truth. Coherence and correspondence. |
| 3884 | The pragmatist does not really have a theory of truth [Scruton] |
| Full Idea: The pragmatist does not really have a theory of truth. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 9.4) |
| 23445 | Naïve set theory says any formula defines a set, and coextensive sets are identical [Linnebo] |
| Full Idea: Naïve set theory is based on the principles that any formula defines a set, and that coextensive sets are identical. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 4.2) | |
| A reaction: The second principle is a standard axiom of ZFC. The first principle causes the trouble. |
| 23447 | In classical semantics singular terms refer, and quantifiers range over domains [Linnebo] |
| Full Idea: In classical semantics the function of singular terms is to refer, and that of quantifiers, to range over appropriate domains of entities. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 7.1) |
| 23443 | The axioms of group theory are not assertions, but a definition of a structure [Linnebo] |
| Full Idea: Considered in isolation, the axioms of group theory are not assertions but comprise an implicit definition of some abstract structure, | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 3.5) | |
| A reaction: The traditional Euclidean approach is that axioms are plausible assertions with which to start. The present idea sums up the modern approach. In the modern version you can work backwards from a structure to a set of axioms. |
| 23444 | To investigate axiomatic theories, mathematics needs its own foundational axioms [Linnebo] |
| Full Idea: Mathematics investigates the deductive consequences of axiomatic theories, but it also needs its own foundational axioms in order to provide models for its various axiomatic theories. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 4.1) | |
| A reaction: This is a problem which faces the deductivist (if-then) approach. The deductive process needs its own grounds. |
| 3907 | Could you be intellectually acquainted with numbers, but unable to count objects? [Scruton] |
| Full Idea: Could someone have a perfect intellectual acquaintance with numbers, but be incapable of counting a flock of sheep? | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 26.6) |
| 23446 | You can't prove consistency using a weaker theory, but you can use a consistent theory [Linnebo] |
| Full Idea: If the 2nd Incompleteness Theorem undermines Hilbert's attempt to use a weak theory to prove the consistency of a strong one, it is still possible to prove the consistency of one theory, assuming the consistency of another theory. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 4.6) | |
| A reaction: Note that this concerns consistency, not completeness. |
| 23448 | Mathematics is the study of all possible patterns, and is thus bound to describe the world [Linnebo] |
| Full Idea: Philosophical structuralism holds that mathematics is the study of abstract structures, or 'patterns'. If mathematics is the study of all possible patterns, then it is inevitable that the world is described by mathematics. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 11.1) | |
| A reaction: [He cites the physicist John Barrow (2010) for this] For me this is a major idea, because the concept of a pattern gives a link between the natural physical world and the abstract world of mathematics. No platonism is needed. |
| 23441 | Logical truth is true in all models, so mathematical objects can't be purely logical [Linnebo] |
| Full Idea: Modern logic requires that logical truths be true in all models, including ones devoid of any mathematical objects. It follows immediately that the existence of mathematical objects can never be a matter of logic alone. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 2) | |
| A reaction: Hm. Could there not be a complete set of models for a theory which all included mathematical objects? (I can't answer that). |
| 23442 | Game Formalism has no semantics, and Term Formalism reduces the semantics [Linnebo] |
| Full Idea: Game Formalism seeks to banish all semantics from mathematics, and Term Formalism seeks to reduce any such notions to purely syntactic ones. | |
| From: Øystein Linnebo (Philosophy of Mathematics [2017], 3.3) | |
| A reaction: This approach was stimulated by the need to justify the existence of the imaginary number i. Just say it is a letter! |
| 3908 | If maths contains unprovable truths, then maths cannot be reduced to a set of proofs [Scruton] |
| Full Idea: If there can be unprovable truths of mathematics, then mathematics cannot be reduced to the proofs whereby we construct it. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 26.7) |
| 3906 | If possible worlds are needed to define properties, maybe we should abandon properties [Scruton] |
| Full Idea: If the only way of defining properties involves quantifying over possible worlds, this could be taken as another reason for abandoning properties altogether. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 26.4) |
| 3888 | Hume assumes that necessity can only be de dicto, not de re [Scruton] |
| Full Idea: It was one of the assumptions of Hume's empiricism that all necessities are de dicto: i.e. they are artefacts of language. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 13.5) |
| 3903 | The conceivable can't be a test of the possible, if there are things which are possible but inconceivable [Scruton] |
| Full Idea: If there are things which are possible but inconceivable, we must abandon the view, which has had a considerable following since Descartes, that the conceivable is a test of the possible. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 25) |
| 3897 | Epistemology is about the justification of belief, not the definition of knowledge [Scruton] |
| Full Idea: In my view the concept of knowledge is of no very great interest in epistemology, which actually concerns the justification of belief. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 22) | |
| A reaction: I think this is an excellent thought. I see knowledge as slippery, and partially contextual, and I don't care whether someone precisely 'knows' something. I just want to know why they believe it. |
| 3881 | In the Cogito argument consciousness develops into self-consciousness [Scruton] |
| Full Idea: In the course of the argument the first person has acquired a character; he is not merely conscious, but self-conscious. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 4) |
| 3887 | Maybe our knowledge of truth and causation is synthetic a priori [Scruton] |
| Full Idea: 'Every event has a cause' and 'truth is correspondence to facts' are candidates for being synthetic a priori knowledge. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 13.2) |
| 3901 | Touch only seems to reveal primary qualities [Scruton] |
| Full Idea: Touch seems to deliver a purely primary-quality account of the world. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 24) | |
| A reaction: Interesting, though a little over-confident. It seems occasionally possible for touch to be an illusion. |
| 3885 | We only conceive of primary qualities as attached to secondary qualities [Scruton] |
| Full Idea: Bradley argued that we cannot conceive of primary qualities except as attached to secondary qualities. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 10.1) |
| 3910 | If primary and secondary qualities are distinct, what has the secondary qualities? [Scruton] |
| Full Idea: If primary and secondary qualities are distinct, what do secondary qualities inhere in? | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], Ch.10 n) | |
| A reaction: What is the problem? A pin causes me pain, but I know the pain isn't in the pin. It is the same with colour. It is a mental property, if you like, triggered by a wavelength of radiation. |
| 3899 | The representational theory says perceptual states are intentional states [Scruton] |
| Full Idea: The representational theory is the unsurprising view that perceptual states are intentional, like beliefs, emotions and desires. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 23.3) |
| 3898 | My belief that it will rain tomorrow can't be caused by its raining tomorrow [Scruton] |
| Full Idea: It is impossible that my present belief that it will rain tomorrow is caused by its raining tomorrow. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 22.4) | |
| A reaction: This doesn't demolish a causal account of belief. It would be very surprising if I were to believe it was going to rain tomorrow for no cause whatsoever. That would be irrational. |
| 3880 | Logical positivism avoids scepticism, by closing the gap between evidence and conclusion [Scruton] |
| Full Idea: If the evidence for p is q, and that is the only evidence there is or can be, then 'p' means q. Hence there is no gap between evidence and conclusion, and the sceptical problem does not arise. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 3.2) |
| 3878 | Why should you believe someone who says there are no truths? [Scruton] |
| Full Idea: A writer who says that there are no truths, or that all truth is 'merely relative', is asking you not to believe him. So don't. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 1.1) |
| 3892 | Every event having a cause, and every event being determined by its cause, are not the same [Scruton] |
| Full Idea: To say that every event has a cause is one thing; to say that every event is determined by its cause is quite another thing. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 17.1) |
| 3911 | The very concept of a substance denies the possibility of mutual interaction and dependence [Scruton] |
| Full Idea: It is often held to be a consequence of the rationalist conception of substance, that separate substances cannot interact (since causal interaction is a form of mutual dependence). | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], Ch.16 n) | |
| A reaction: Yes, substances seem incapable of interaction, just as Leibniz argues that perfections could never interact. They are too pure. |
| 3882 | Wittgenstein makes it impossible to build foundations from something that is totally private [Scruton] |
| Full Idea: Wittgenstein's point is that if I search for foundations in what can only be known to me, then the belief that I have discovered those foundations will also fall victim to Descartes' demon. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 5.3) | |
| A reaction: Why should foundations based in wider society or a language community fare any better? Getting a lot of people to agree won't trouble the demon too much. Flat earthers. |
| 5121 | Basing ethics on flourishing makes it consequentialist, as actions are judged by contributing to it [Harman] |
| Full Idea: Basing ethics on human flourishing tends towards utilitarianism or consequentialism; actions, character traits, laws, and so on are to be assessed with reference to their contributions to human flourishing. | |
| From: Gilbert Harman (Human Flourishing, Ethics and Liberty [1983], 9.2.2) | |
| A reaction: This raises the question of whether only virtue can contribute to flourishing, or whether a bit of vice might be helpful. This problem presumably pushed the Stoics to say that virtue itself is the good, rather than the resulting flourishing. |
| 5120 | What counts as 'flourishing' must be relative to various sets of values [Harman] |
| Full Idea: If we base our ethics on human flourishing, one implication would seem to be moral relativism, since what counts as 'flourishing' seems inevitably relative to one or other set of values. | |
| From: Gilbert Harman (Human Flourishing, Ethics and Liberty [1983], 9.2.1) | |
| A reaction: This remark seems to make the relativist assumption that all value systems are equal. For Aristotle, flourishing is no more relative than health is. No one can assert that illness has an intrinsically high value in human life. |
| 3896 | Any social theory of morality has the problem of the 'free rider', who only pretends to join in [Scruton] |
| Full Idea: Any attempt to provide a social justification of morality runs the risk of the 'free rider' - one who pretends to play the game in order to enjoy the fruits of it. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 20.6) |
| 3886 | Membership is the greatest source of obligation [Scruton] |
| Full Idea: Membership is the greatest source of obligation. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 11.2) | |
| A reaction: An interesting and rather Aristotelian idea. The alternative is individual debt or obligation. |
| 3895 | The categorical imperative is not just individual, but can be used for negotiations between strangers [Scruton] |
| Full Idea: The categorical imperative is also an instrument of negotiation and compromise between strangers, through which they can rise out of enmity and confront each other as equals. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 20.6) |
| 3890 | 'Cause' used to just mean any valid explanation [Scruton] |
| Full Idea: Traditionally (before Leibniz and Spinoza) the world 'cause' signified any valid explanation. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 14) |
| 3904 | Measuring space requires no movement while I do it [Scruton] |
| Full Idea: I can measure the length of something only if I know that it has not moved between the moment when I locate one end of it and the moment when I locate the other. | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 25.3) | |
| A reaction: A nice example of how even simple propositions have many presuppositions. |
| 3905 | 'Existence' is not a predicate of 'man', but of the concept of man, saying it has at least one instance [Scruton] |
| Full Idea: When I say that a man exists, Frege argues, I do not predicate existence of a man, but rather of the concept man: I say the concept has at least one instance (and existence is a predicate of predicates). | |
| From: Roger Scruton (Modern Philosophy:introduction and survey [1994], 26.2) |