47 ideas
16943 | Philosophy is continuous with science, and has no external vantage point [Quine] |
Full Idea: I see philosophy not as an a priori propaedeutic or groundwork for science, but as continuous with science. I see philosophy and science as in the same boat. …There is no external vantage point, no first philosophy. | |
From: Willard Quine (Natural Kinds [1969], p.126) | |
A reaction: Philosophy is generalisation. Science holds the upper hand, because it settles the subject-matter to be generalised. |
4642 | No fact can be real and no proposition true unless there is a Sufficient Reason (even if we can't know it) [Leibniz] |
Full Idea: The principle of sufficient reason says no fact can be real or existing and no proposition can be true unless there is a sufficient reason why it should be thus and not otherwise, even though in most cases these reasons cannot be known to us. | |
From: Gottfried Leibniz (Monadology [1716], §32) | |
A reaction: I think of this as my earliest philosophical perception, a childish rebellion against being told that there was 'no reason' for something. My intuition tells me that it is correct, and the foundation of ontology and truth. Don't ask me to justify it! |
9108 | From an impossibility anything follows [William of Ockham] |
Full Idea: From an impossibility anything follows ('quod ex impossibili sequitur quodlibet'). | |
From: William of Ockham (Summa totius logicae [1323], III.c.xxxvi) | |
A reaction: The hallmark of a true logician, I suspect, is that this opinion is really meaningful and important to them. They yearn to follow the logic wherever it leads. Common sense would seem to say that absolutely nothing follows from an impossibility. |
9107 | A proposition is true if its subject and predicate stand for the same thing [William of Ockham] |
Full Idea: If in the proposition 'This is an angel' subject and predicate stand for the same thing, the proposition is true. | |
From: William of Ockham (Summa totius logicae [1323], II.c.ii) | |
A reaction: An interesting statement of what looks like a correspondence theory, employing the idea that both the subject and the predicate have a reference. I think Frege would say that 'x is an angel' is unsaturated, and so lacks reference. |
2115 | Everything in the universe is interconnected, so potentially a mind could know everything [Leibniz] |
Full Idea: Every body is sensitive to everything in the universe, so that one who saw everything could read in each body what is happening everywhere, and even what has happened and will happen. | |
From: Gottfried Leibniz (Monadology [1716], §61) |
16300 | Ockham had an early axiomatic account of truth [William of Ockham, by Halbach] |
Full Idea: Theories structurally very similar to axiomatic compositional theories of truth can be found in Ockham's 'Summa Logicae'. | |
From: report of William of Ockham (Summa totius logicae [1323]) by Volker Halbach - Axiomatic Theories of Truth 3 |
2111 | Falsehood involves a contradiction, and truth is contradictory of falsehood [Leibniz] |
Full Idea: We judge to be false that which involves a contradiction, and true that which is opposed or contradictory to the false. | |
From: Gottfried Leibniz (Monadology [1716], §31) |
9106 | The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham] |
Full Idea: The syncategorematic word 'every' does not signify any fixed thing, but when added to 'man' it makes the term 'man' stand for all men actually. | |
From: William of Ockham (Summa totius logicae [1323], I.c.iv) | |
A reaction: Although quantifiers may have become a part of formal logic with Frege, their importance is seen from Aristotle onwards, and it is clearly a key part of William's understanding of logic. |
16949 | Klein summarised geometry as grouped together by transformations [Quine] |
Full Idea: Felix Klein's so-called 'Erlangerprogramm' in geometry involved characterizing the various branches of geometry by what transformations were irrelevant to each. | |
From: Willard Quine (Natural Kinds [1969], p.137) |
9113 | Just as unity is not a property of a single thing, so numbers are not properties of many things [William of Ockham] |
Full Idea: Number is nothing but the actual numbered things themselves. Hence just as unity is not an accident added to the thing which is one, so number is not an accident of the things which are numbered. | |
From: William of Ockham (Summa totius logicae [1323], I.c.xliv) | |
A reaction: [William does not necessarily agree with this view] It strikes me as a key point here that any account of the numbers had better work for 'one', though 'zero' might be treated differently. Some people seem to think unity is a property of things. |
9110 | The words 'thing' and 'to be' assert the same idea, as a noun and as a verb [William of Ockham] |
Full Idea: The words 'thing' and 'to be' (esse) signify one and the same thing, but the one in the manner of a noun and the other in the manner of a verb. | |
From: William of Ockham (Summa totius logicae [1323], III,II,c,xxvii) | |
A reaction: Well said - as you would expect from a thoroughgoing nominalist. I would have thought that this was the last word on the subject of Being, thus rendering any need for me to read Heidegger quite superfluous. Or am I missing something? |
7644 | The monad idea incomprehensibly spiritualises matter, instead of materialising soul [La Mettrie on Leibniz] |
Full Idea: The Leibnizians with their monads have constructed an incomprehensible hypothesis. They have spiritualized matter rather than materialising the soul. | |
From: comment on Gottfried Leibniz (Monadology [1716]) by Julien Offray de La Mettrie - Machine Man p.3 | |
A reaction: I agree with La Mettrie. This disagreement shows, I think, how important the problem of interaction between mind and body was in the century after Descartes. Drastic action seemed needed to bridge the gap, one way or the other. |
11857 | He replaced Aristotelian continuants with monads [Leibniz, by Wiggins] |
Full Idea: In the end Leibniz dethroned Aristotelian continuants, seen as imperfect from his point of view, in favour of monads. | |
From: report of Gottfried Leibniz (Monadology [1716]) by David Wiggins - Sameness and Substance Renewed 3.1 | |
A reaction: I take the 'continuants' to be either the 'ultimate subject of predication' (in 'Categories'), or 'essences' (in 'Metaphysics'). Since monads seem to be mental (presumably to explain the powers of things), this strikes me as a bit mad. |
7843 | Is a drop of urine really an infinity of thinking monads? [Voltaire on Leibniz] |
Full Idea: Can you really maintain that a drop of urine is an infinity of monads, and that each one of these has ideas, however obscure, of the entire universe? | |
From: comment on Gottfried Leibniz (Monadology [1716]) by Francois-Marie Voltaire - works Vol 22:434 | |
A reaction: Monads are a bit like Christian theology - if you meet them cold they seem totally ridiculous, but if you meet them after ten years of careful preliminary study they make (apparently) complete sense. Defenders of panpsychism presumably like them. |
12751 | It is unclear in 'Monadology' how extended bodies relate to mind-like monads. [Garber on Leibniz] |
Full Idea: It is never clear in the 'Monadologie' how exactly the world of extended bodies is related to the world of simple substances, the world of non-extended and mind-like monads. | |
From: comment on Gottfried Leibniz (Monadology [1716]) by Daniel Garber - Leibniz:Body,Substance,Monad 9 | |
A reaction: Leibniz was always going to hit the interaction problem, as soon as he started giving an increasingly spiritual account of what a substance, and hence marginalising the 'force' which had held centre-stage earlier on. Presumably they are 'parallel'. |
19363 | Changes in a monad come from an internal principle, and the diversity within its substance [Leibniz] |
Full Idea: A monad's natural changes come from an internal principle, ...but there must be diversity in that which changes, which produces the specification and variety of substances. | |
From: Gottfried Leibniz (Monadology [1716], §11-12) | |
A reaction: You don't have to like monads to like this generalisation (and Perkins says Leibniz had a genius for generalisations). Metaphysics must give an account of change. Succeeding time-slices etc explain nothing. Principle and substance must meet. |
19352 | A 'monad' has basic perception and appetite; a 'soul' has distinct perception and memory [Leibniz] |
Full Idea: The general name 'monad' or 'entelechy' may suffice for those substances which have nothing but perception and appetition; the name 'souls' may be reserved for those having perception that is more distinct and accompanied by memory. | |
From: Gottfried Leibniz (Monadology [1716], §19) | |
A reaction: It is basic to the study of Leibniz that you don't think monads are full-blown consciousnesses. He isn't really a panpsychist, because the level of mental activity is so minimal. There seem to be degrees of monadhood. |
16939 | Mass terms just concern spread, but other terms involve both spread and individuation [Quine] |
Full Idea: 'Yellow' and 'water' are mass terms, concerned only with spread; 'apple' and 'square' are terms of divided reference, concerned with both spread and individuation. | |
From: Willard Quine (Natural Kinds [1969], p.124) | |
A reaction: Would you like some apple? Pass me that water. It is helpful to see that it is a requirement of 'individuation' that is missing from terms for stuff. |
16948 | Once we know the mechanism of a disposition, we can eliminate 'similarity' [Quine] |
Full Idea: Once we can legitimize a disposition term by defining the relevant similarity standard, we are apt to know the mechanism of the disposition, and so by-pass the similarity. | |
From: Willard Quine (Natural Kinds [1969], p.135) | |
A reaction: I love mechanisms, but can we characterise mechanisms without mentioning powers and dispositions? Quine's dream is to eliminate 'similarity'. |
16945 | We judge things to be soluble if they are the same kind as, or similar to, things that do dissolve [Quine] |
Full Idea: Intuitively, what qualifies a thing as soluble though it never gets into water is that it is of the same kind as the things that actually did or will dissolve; it is similar to them. | |
From: Willard Quine (Natural Kinds [1969], p.130) | |
A reaction: If you can judge that the similar things 'will' dissolve, you can cut to the chase and judge that this thing will dissolve. |
15388 | Universals are single things, and only universal in what they signify [William of Ockham] |
Full Idea: Every universal is one particular thing and it is not a universal except in its signification, in its signifying many thing. | |
From: William of Ockham (Summa totius logicae [1323]), quoted by Claude Panaccio - Medieval Problem of Universals 'William' | |
A reaction: Sounds as if William might have liked tropes. It seems to leave the problem unanswered (the 'ostrich' problem?). How are they able to signify in this universal way, if each thing is just distinct and particular? |
7931 | If a substance is just a thing that has properties, it seems to be a characterless non-entity [Leibniz, by Macdonald,C] |
Full Idea: For Leibniz, to distinguish between a substance and its properties in order to provide a thing or entity in which properties can inhere leads necessarily to the absurd conclusion that the substance itself must be a truly characterless non-entity. | |
From: report of Gottfried Leibniz (Monadology [1716]) by Cynthia Macdonald - Varieties of Things Ch.3 | |
A reaction: This is obviously one of the basic thoughts in any discussion of substances. It is why physicists ignore them, and Leibniz opted for a 'bundle' theory. But the alternative seems daft too - free-floating properties, hooked onto one another. |
9109 | If essence and existence were two things, one could exist without the other, which is impossible [William of Ockham] |
Full Idea: If essence and existence were two things, then no contradiction would be involved if God preserved the essence of a thing in the world without its existence, or vice versa, its existence without its essence; both of which are impossible. | |
From: William of Ockham (Summa totius logicae [1323], III,II,c,xxvii) | |
A reaction: Not that William is using the concept of a supreme mind as a tool in argument. His denial of essence as something separable is presumably his denial of the Aristotelian view of universals, as well as of the Platonic view. |
17554 | There must be some internal difference between any two beings in nature [Leibniz] |
Full Idea: There are never two beings in nature that are perfectly alike, two beings in which it is not possible to discover an internal difference, that is, one founded on an intrinsic denomination. | |
From: Gottfried Leibniz (Monadology [1716], §09) | |
A reaction: From this it follows that if two things really are indiscernible, then we must say that they are one thing. He says monads all differ from one another. People certainly do. Leibniz must say this of electrons. How can he know this? |
2112 | Truths of reason are known by analysis, and are necessary; facts are contingent, and their opposites possible [Leibniz] |
Full Idea: There are two kinds of truths: of reasoning and of facts. Truths of reasoning are necessary and their opposites impossible. Facts are contingent and their opposites possible. A necessary truth is known by analysis. | |
From: Gottfried Leibniz (Monadology [1716], §33) |
9344 | Mathematical analysis ends in primitive principles, which cannot be and need not be demonstrated [Leibniz] |
Full Idea: At the end of the analytical method in mathematics there are simple ideas of which no definition can be given. Moreover there are axioms and postulates, in short, primitive principles, which cannot be demonstrated and do not need demonstration. | |
From: Gottfried Leibniz (Monadology [1716], §35) | |
A reaction: My view is that we do not know such principles when we apprehend them in isolation. I would call them 'intuitions'. They only ascend to the status of knowledge when the mathematics is extended and derived from them, and found to work. |
2110 | We all expect the sun to rise tomorrow by experience, but astronomers expect it by reason [Leibniz] |
Full Idea: When we expect it to be day tomorrow, we all behave as empiricists, because until now it has always happened thus. The astronomer alone knows this by reason. | |
From: Gottfried Leibniz (Monadology [1716], §28) |
16944 | Science is common sense, with a sophisticated method [Quine] |
Full Idea: Sciences differ from common sense only in the degree of methodological sophistication. | |
From: Willard Quine (Natural Kinds [1969], p.129) | |
A reaction: Science is normal thinking about the world, but it is teamwork, with the bar set very high. |
16940 | Induction is just more of the same: animal expectations [Quine] |
Full Idea: Induction is essentially only more of the same: animal expectation or habit formation. | |
From: Willard Quine (Natural Kinds [1969], p.125) | |
A reaction: My working definition of induction is 'learning from experience', but that doesn't disagree with Quine. Lipton has a richer account of different types of induction. Quine's point is that it rests on resemblance. |
16941 | Induction relies on similar effects following from each cause [Quine] |
Full Idea: Induction expresses our hopes that similar causes will have similar effects. | |
From: Willard Quine (Natural Kinds [1969], p.125) | |
A reaction: Some top philosophers are also top teachers, and Quine was one of them, in his writings. He boils it down for the layman. Once again, he is pointing to the fundamental role of the similarity relation. |
16933 | Grue is a puzzle because the notions of similarity and kind are dubious in science [Quine] |
Full Idea: What makes Goodman's example a puzzle is the dubious scientific standing of a general notion of similarity, or of kind. | |
From: Willard Quine (Natural Kinds [1969], p.116) | |
A reaction: Illuminating. It might be best expressed as revealing a problem with sortal terms, as employed by Geach, or by Wiggins. Grue is a bit silly, but sortals are subject to convention and culture. 'Natural' properties seem needed. |
2109 | Increase a conscious machine to the size of a mill - you still won't see perceptions in it [Leibniz] |
Full Idea: If a conscious machine were increased in size, one might enter it like a mill, but we should only see the parts impinging on one another; we should not see anything which would explain a perception. | |
From: Gottfried Leibniz (Monadology [1716], §17) | |
A reaction: A wonderful image for capturing a widely held intuition. It seems to motivate Colin McGinn's 'Mysterianism'. The trouble is Leibniz didn't think big/small enough. Down at the level of molecules it might become obvious what a perception is. 'Might'. |
16934 | General terms depend on similarities among things [Quine] |
Full Idea: The usual general term, whether a common noun or a verb or an adjective, owes its generality to some resemblance among the things referred to. | |
From: Willard Quine (Natural Kinds [1969], p.116) | |
A reaction: Quine has a nice analysis of the basic role of similarity in a huge amount of supposedly strict scientific thought. |
16938 | To learn yellow by observation, must we be told to look at the colour? [Quine] |
Full Idea: According to the 'respects' view, our learning of yellow by ostension would have depended on our first having been told or somehow apprised that it was going to be a question of color. | |
From: Willard Quine (Natural Kinds [1969], p.122) | |
A reaction: Quine suggests there is just one notion of similarity, and respects can be 'abstracted' afterwards. Even the ontologically ruthless Quine admits psychological abstraction! |
8486 | Standards of similarity are innate, and the spacing of qualities such as colours can be mapped [Quine] |
Full Idea: A standard of similarity is in some sense innate. The spacing of qualities (such as red, pink and blue) can be explored and mapped in the laboratory by experiments. They are needed for all learning. | |
From: Willard Quine (Natural Kinds [1969], p.123) | |
A reaction: This reasserts Hume's original point in more scientific terms. It is one of the undeniable facts about our perceptions of qualities and properties, no matter how platonist your view of universals may be. |
16947 | Similarity is just interchangeability in the cosmic machine [Quine] |
Full Idea: Things are similar to the extent that they are interchangeable parts of the cosmic machine. | |
From: Willard Quine (Natural Kinds [1969], p.134) | |
A reaction: This is a major idea for Quine, because it is a means to gradually eliminate the fuzzy ideas of 'resemblance' or 'similarity' or 'natural kind' from science. I love it! Two tigers are same insofar as they are substitutable. |
19362 | We know the 'I' and its contents by abstraction from awareness of necessary truths [Leibniz] |
Full Idea: It is through the knowledge of necessary truths and through their abstraction that we rise to reflective acts, which enable us to think of that which is called "I" and enable us to consider that this or that is in us. | |
From: Gottfried Leibniz (Monadology [1716], §30) | |
A reaction: For Leibniz, necessary truth can only be known a priori. Sense experience won't reveal the self, as Hume observed. We evidently 'abstract' the idea of 'I' from the nature of a priori thought. Animals have no self (or morals) for this reason. |
16932 | Projectible predicates can be universalised about the kind to which they refer [Quine] |
Full Idea: 'Projectible' predicates are predicates F and G whose shared instances all do count, for whatever reason, towards confirmation of 'All F are G'. ….A projectible predicate is one that is true of all and only the things of a kind. | |
From: Willard Quine (Natural Kinds [1969], p.115-6) | |
A reaction: Both Quine and Goodman are infuriatingly brief about the introduction of this concept. 'Red' is true of all ripe tomatoes, but not 'only' of them. Hardly any predicates are true only of one kind. Is that a scholastic 'proprium'? |
9105 | Some concepts for propositions exist only in the mind, and in no language [William of Ockham] |
Full Idea: Conceptual terms and the propositions formed by them are those mental words which do not belong to any language; they remain only in the mind and cannot be uttered exteriorly, though signs subordinated to these can be exteriorly uttered. | |
From: William of Ockham (Summa totius logicae [1323], I.c.i) | |
A reaction: [He cites Augustine] A glimmer of the idea of Mentalese, and is probably an integral part of any commitment to propositions. Quine would hate it, but I like it. Logicians seem to dislike anything that cannot be articulated, but brains are like that. |
12707 | The true elements are atomic monads [Leibniz] |
Full Idea: Monads are the true atoms of nature and, in brief, the elements of things. | |
From: Gottfried Leibniz (Monadology [1716], (opening)), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 2 | |
A reaction: Thus in one sentence Leibniz gives us a theory of natural elements, and an account of atoms. This kind of speculation got metaphysics a bad name when science unravelled a more accurate picture. The bones must be picked out of Leibniz. |
7375 | Quine probably regrets natural kinds now being treated as essences [Quine, by Dennett] |
Full Idea: The concept of natural kinds was reintroduced by Quine, who may now regret the way it has become a stand-in for the dubious but covertly popular concept of essences. | |
From: report of Willard Quine (Natural Kinds [1969]) by Daniel C. Dennett - Consciousness Explained 12.2 n2 | |
A reaction: He is right that Quine would regret it, and he is right that we can't assume that there are necessary essences just because there seem to be stable natural kinds, but personally I am an essentialist, so I'm not that bothered. |
16935 | If similarity has no degrees, kinds cannot be contained within one another [Quine] |
Full Idea: If similarity has no degrees there is no containing of kinds within broader kinds. If colored things are a kind, they are similar, but red things are too narrow for a kind. If red things are a kind, colored things are not similar, and it's too broad. | |
From: Willard Quine (Natural Kinds [1969], p.118) | |
A reaction: [compressed] I'm on Quine's side with this. We glibly talk of 'kinds', but the criteria for sorting things into kinds seems to be a mess. Quine goes on to offer a better account than the (diadic, yes-no) one rejected here. |
16936 | Comparative similarity allows the kind 'colored' to contain the kind 'red' [Quine] |
Full Idea: With the triadic relation of comparative similarity, kinds can contain one another, as well as overlapping. Red and colored things can both count as kinds. Colored things all resemble one another, even though less than red things do. | |
From: Willard Quine (Natural Kinds [1969], p.119) | |
A reaction: [compressed] Quine claims that comparative similarity is necessary for kinds - that there be some 'foil' in a similarity - that A is more like C than B is. |
16937 | You can't base kinds just on resemblance, because chains of resemblance are a muddle [Quine] |
Full Idea: If kinds are based on similarity, this has the Imperfect Community problem. Red round, red wooden and round wooden things all resemble one another somehow. There may be nothing outside the set resembling them, so it meets the definition of kind. | |
From: Willard Quine (Natural Kinds [1969], p.120) | |
A reaction: [ref. to Goodman 'Structure' 2nd 163- , which attacks Carnap on this] This suggests an invocation of Wittgenstein's family resemblance, which won't be much help for natural kinds. |
16942 | It is hard to see how regularities could be explained [Quine] |
Full Idea: Why there have been regularities is an obscure question, for it is hard to see what would count as an answer. | |
From: Willard Quine (Natural Kinds [1969], p.126) | |
A reaction: This is the standard pessimism of the 20th century Humeans, but it strikes me as comparable to the pessimism about science found in Locke and Hume. Regularities are explained all the time by scientists, though the lowest level may be hopeless. |
2114 | This is the most perfect possible universe, in its combination of variety with order [Leibniz] |
Full Idea: From all the possible universes God chooses this one to obtain as much variety as possible, but with the greatest order possible; that is, it is the means of obtaining the greatest perfection possible. | |
From: Gottfried Leibniz (Monadology [1716], §58) |
2113 | God alone (the Necessary Being) has the privilege that He must exist if He is possible [Leibniz] |
Full Idea: God alone (or the Necessary Being) has the privilege that He must exist if He is possible. | |
From: Gottfried Leibniz (Monadology [1716], §45) |