59 ideas
| 18074 | Intuitionists rely on assertability instead of truth, but assertability relies on truth [Kitcher] |
| Full Idea: Though it may appear that the intuitionist is providing an account of the connectives couched in terms of assertability conditions, the notion of assertability is a derivative one, ultimately cashed out by appealing to the concept of truth. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.5) | |
| A reaction: I have quite a strong conviction that Kitcher is right. All attempts to eliminate truth, as some sort of ideal at the heart of ordinary talk and of reasoning, seems to me to be doomed. |
| 6298 | Kitcher says maths is an idealisation of the world, and our operations in dealing with it [Kitcher, by Resnik] |
| Full Idea: Kitcher says maths is an 'idealising theory', like some in physics; maths idealises features of the world, and practical operations, such as segregating and matching (numbering), measuring, cutting, moving, assembling (geometry), and collecting (sets). | |
| From: report of Philip Kitcher (The Nature of Mathematical Knowledge [1984]) by Michael D. Resnik - Maths as a Science of Patterns One.4.2.2 | |
| A reaction: This seems to be an interesting line, which is trying to be fairly empirical, and avoid basing mathematics on purely a priori understanding. Nevertheless, we do not learn idealisation from experience. Resnik labels Kitcher an anti-realist. |
| 12392 | Mathematical a priorism is conceptualist, constructivist or realist [Kitcher] |
| Full Idea: Proposals for a priori mathematical knowledge have three main types: conceptualist (true in virtue of concepts), constructivist (a construct of the human mind) and realist (in virtue of mathematical facts). | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 02.3) | |
| A reaction: Realism is pure platonism. I think I currently vote for conceptualism, with the concepts deriving from the concrete world, and then being extended by fictional additions, and shifts in the notion of what 'number' means. |
| 18078 | The interest or beauty of mathematics is when it uses current knowledge to advance undestanding [Kitcher] |
| Full Idea: What makes a question interesting or gives it aesthetic appeal is its focussing of the project of advancing mathematical understanding, in light of the concepts and systems of beliefs already achieved. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 09.3) | |
| A reaction: Kitcher defends explanation (the source of understanding, presumably) in terms of unification with previous theories (the 'concepts and systems'). I always have the impression that mathematicians speak of 'beauty' when they see economy of means. |
| 12426 | The 'beauty' or 'interest' of mathematics is just explanatory power [Kitcher] |
| Full Idea: Insofar as we can honor claims about the aesthetic qualities or the interest of mathematical inquiries, we should do so by pointing to their explanatory power. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 09.4) | |
| A reaction: I think this is a good enough account for me (but probably not for my friend Carl!). Beautiful cars are particularly streamlined. Beautiful people look particularly healthy. A beautiful idea is usually wide-ranging. |
| 12395 | Real numbers stand to measurement as natural numbers stand to counting [Kitcher] |
| Full Idea: The real numbers stand to measurement as the natural numbers stand to counting. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.4) |
| 12425 | Complex numbers were only accepted when a geometrical model for them was found [Kitcher] |
| Full Idea: An important episode in the acceptance of complex numbers was the development by Wessel, Argand, and Gauss, of a geometrical model of the numbers. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 07.5) | |
| A reaction: The model was in terms of vectors and rotation. New types of number are spurned until they can be shown to integrate into a range of mathematical practice, at which point mathematicians change the meaning of 'number' (without consulting us). |
| 18071 | A one-operation is the segregation of a single object [Kitcher] |
| Full Idea: We perform a one-operation when we perform a segregative operation in which a single object is segregated. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.3) | |
| A reaction: This is part of Kitcher's empirical but constructive account of arithmetic, which I find very congenial. He avoids the word 'unit', and goes straight to the concept of 'one' (which he treats as more primitive than zero). |
| 18066 | The old view is that mathematics is useful in the world because it describes the world [Kitcher] |
| Full Idea: There is an old explanation of the utility of mathematics. Mathematics describes the structural features of our world, features which are manifested in the behaviour of all the world's inhabitants. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.1) | |
| A reaction: He only cites Russell in modern times as sympathising with this view, but Kitcher gives it some backing. I think the view is totally correct. The digression produced by Cantorian infinities has misled us. |
| 18083 | With infinitesimals, you divide by the time, then set the time to zero [Kitcher] |
| Full Idea: The method of infinitesimals is that you divide by the time, and then set the time to zero. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 10.2) |
| 12393 | Intuition is no basis for securing a priori knowledge, because it is fallible [Kitcher] |
| Full Idea: The process of pure intuition does not measure up to the standards required of a priori warrants not because it is sensuous but because it is fallible. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 03.2) |
| 18061 | Mathematical intuition is not the type platonism needs [Kitcher] |
| Full Idea: The intuitions of which mathematicians speak are not those which Platonism requires. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 03.3) | |
| A reaction: The point is that it is not taken to be a 'special' ability, but rather a general insight arising from knowledge of mathematics. I take that to be a good account of intuition, which I define as 'inarticulate rationality'. |
| 12420 | If mathematics comes through intuition, that is either inexplicable, or too subjective [Kitcher] |
| Full Idea: If mathematical statements are don't merely report features of transient and private mental entities, it is unclear how pure intuition generates mathematical knowledge. But if they are, they express different propositions for different people and times. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 03.1) | |
| A reaction: This seems to be the key dilemma which makes Kitcher reject intuition as an a priori route to mathematics. We do, though, just seem to 'see' truths sometimes, and are unable to explain how we do it. |
| 12387 | Mathematical knowledge arises from basic perception [Kitcher] |
| Full Idea: Mathematical knowledge arises from rudimentary knowledge acquired by perception. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], Intro) | |
| A reaction: This is an empiricist manifesto, which asserts his allegiance to Mill, and he gives a sophisticated account of how higher mathematics can be accounted for in this way. Well, he tries to. |
| 12412 | My constructivism is mathematics as an idealization of collecting and ordering objects [Kitcher] |
| Full Idea: The constructivist position I defend claims that mathematics is an idealized science of operations which can be performed on objects in our environment. It offers an idealized description of operations of collecting and ordering. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], Intro) | |
| A reaction: I think this is right. What is missing from Kitcher's account (and every other account I've met) is what is meant by 'idealization'. How do you go about idealising something? Hence my interest in the psychology of abstraction. |
| 18065 | We derive limited mathematics from ordinary things, and erect powerful theories on their basis [Kitcher] |
| Full Idea: I propose that a very limited amount of our mathematical knowledge can be obtained by observations and manipulations of ordinary things. Upon this small base we erect the powerful general theories of modern mathematics. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 05.2) | |
| A reaction: I agree. The three related processes that take us from the experiential base of mathematics to its lofty heights are generalisation, idealisation and abstraction. |
| 18077 | The defenders of complex numbers had to show that they could be expressed in physical terms [Kitcher] |
| Full Idea: Proponents of complex numbers had ultimately to argue that the new operations shared with the original paradigms a susceptibility to construal in physical terms. The geometrical models of complex numbers answered to this need. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 07.5) | |
| A reaction: [A nice example of the verbose ideas which this website aims to express in plain English!] The interest is not that they had to be described physically (which may pander to an uninformed audience), but that they could be so described. |
| 12423 | Analyticity avoids abstract entities, but can there be truth without reference? [Kitcher] |
| Full Idea: Philosophers who hope to avoid commitment to abstract entities by claiming that mathematical statements are analytic must show how analyticity is, or provides a species of, truth not requiring reference. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 04.I) | |
| A reaction: [the last part is a quotation from W.D. Hart] Kitcher notes that Frege has a better account, because he provides objects to which reference can be made. I like this idea, which seems to raise a very large question, connected to truthmakers. |
| 18069 | Arithmetic is an idealizing theory [Kitcher] |
| Full Idea: I construe arithmetic as an idealizing theory. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.2) | |
| A reaction: I find 'generalising' the most helpful word, because everyone seems to understand and accept the idea. 'Idealisation' invokes 'ideals', which lots of people dislike, and lots of philosophers seem to have trouble with 'abstraction'. |
| 18068 | Arithmetic is made true by the world, but is also made true by our constructions [Kitcher] |
| Full Idea: I want to suggest both that arithmetic owes its truth to the structure of the world and that arithmetic is true in virtue of our constructive activity. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.2) | |
| A reaction: Well said, but the problem seems no more mysterious to me than the fact that trees grow in the woods and we build houses out of them. I think I will declare myself to be an 'empirical constructivist' about mathematics. |
| 18070 | We develop a language for correlations, and use it to perform higher level operations [Kitcher] |
| Full Idea: The development of a language for describing our correlational activity itself enables us to perform higher level operations. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.2) | |
| A reaction: This is because all language itself (apart from proper names) is inherently general, idealised and abstracted. He sees the correlations as the nested collections expressed by set theory. |
| 18072 | Constructivism is ontological (that it is the work of an agent) and epistemological (knowable a priori) [Kitcher] |
| Full Idea: The constructivist ontological thesis is that mathematics owes its truth to the activity of an actual or ideal subject. The epistemological thesis is that we can have a priori knowledge of this activity, and so recognise its limits. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.5) | |
| A reaction: The mention of an 'ideal' is Kitcher's personal view. Kitcher embraces the first view, and rejects the second. |
| 18063 | Conceptualists say we know mathematics a priori by possessing mathematical concepts [Kitcher] |
| Full Idea: Conceptualists claim that we have basic a priori knowledge of mathematical axioms in virtue of our possession of mathematical concepts. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 04.1) | |
| A reaction: I sympathise with this view. If concepts are reasonably clear, they will relate to one another in certain ways. How could they not? And how else would you work out those relations other than by thinking about them? |
| 18064 | If meaning makes mathematics true, you still need to say what the meanings refer to [Kitcher] |
| Full Idea: Someone who believes that basic truths of mathematics are true in virtue of meaning is not absolved from the task of saying what the referents of mathematical terms are, or ...what mathematical reality is like. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 04.6) | |
| A reaction: Nice question! He's a fan of getting at the explanatory in mathematics. |
| 12747 | Monads are not extended, but have a kind of situation in extension [Leibniz] |
| Full Idea: Even if monads are not extended, they nonetheless have a certain kind of situation in extension. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 8 | |
| A reaction: This is the kind of metaphysical mess you get into if you start from the wrong premisses (in this case, a dualism of the spiritual and the material). Later (Garber p.359) he says they are situated because they 'preside' over a mass. |
| 12748 | Only monads are substances, and bodies are collections of them [Leibniz] |
| Full Idea: A monad alone is a substance; a body is substances not a substance. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704.01.21), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 8 | |
| A reaction: So how many monads in a drop of urine, as Voltaire bluntly wondered. I take the Cartesian dualism (without interaction) that ran through Leibniz's career to be the source of most of his metaphysical problems. In late career it went badly wrong. |
| 13184 | The division of nature into matter makes distinct appearances, and that presupposes substances [Leibniz] |
| Full Idea: If there were no divisions of matter in nature, there would be no things that are different; just the mere possibility of things. It is the actual division into masses that really produces things that appear distinct, which presupposes simple substances. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704 or 1705) | |
| A reaction: This shows Leibniz to be a straightforward realist about the physical world, and certainly not an 'idealist', despite the mind-like character of monads. I take this to be an argument for reality from best explanation, which is all that's available. |
| 13188 | The only indications of reality are agreement among phenomena, and their agreement with necessities [Leibniz] |
| Full Idea: We don't have, nor should we hope for, any mark of reality in phenomena, but the fact that they agree with one another and with eternal truths. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1706.01.19) | |
| A reaction: Elsewhere he says that divisions in appearance imply divisions in matter. Now he adds two further arguments in favour of realism, but admits that nothing conclusive is available. Quite right. |
| 12752 | Only unities have any reality [Leibniz] |
| Full Idea: There is no reality in anything except the reality of unities. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704.06.30), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 9 | |
| A reaction: This seems to leave indeterminate stuff like air and water with no reality, as nicely discussed by Henry Laycock. Do we just force unities on the world because that is the only way our minds can cope with it? |
| 13187 | In actual things nothing is indefinite [Leibniz] |
| Full Idea: In actual things nothing is indefinite. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1706.01.19) | |
| A reaction: This seems to be the germ of the controversial modern view of Williamson, that vagueness is entirely epistemic, and that the facts of nature are entirely definite. Thus there is a tallest short giraffe, which I find a bit hard to grasp. |
| 19383 | A man's distant wife dying is a real change in him [Leibniz] |
| Full Idea: No one can become a widower in India because of the death of his wife in Europe unless a real change occurs in him. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], GP ii 240), quoted by Richard T.W. Arthur - Leibniz 7 'Nominalist' | |
| A reaction: This is Leibniz heroically denying so-called 'Cambridge Change'. It is hard to see how a widower is changed if he has not yet heard the bad news. But his situation in life has changed. Compare eudaimonia, which you can lose without realising it. |
| 13179 | A complete monad is a substance with primitive active and passive power [Leibniz] |
| Full Idea: What I take to be the indivisible or complete monad is the substance endowed with primitive power, active and passive, like the 'I' or something similar. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20) | |
| A reaction: I love powers, so I really like this quotation. By this date even Garber thinks that he has more or less arrived at his mature view of monads. I used to think monads were mad, but I now think he is closing in on the right answer - sort of. |
| 12749 | Derivate forces are in phenomena, but primitive forces are in the internal strivings of substances [Leibniz] |
| Full Idea: I relegate derivative forces to the phenomena, but I think that it is clear that primitive forces can be nothing other than the internal strivings of simple substances. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1705.01), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 8 | |
| A reaction: I like 'internal strivings', which sounds to me like the Will to Power (Idea 7140). There seems to be an epistemological challenge in trying to disentangle the derivative forces from the primitive ones. |
| 12722 | Thought terminates in force, rather than extension [Leibniz] |
| Full Idea: I believe that our thought is completed and terminated more in the notion of the dynamic [i.e. force] than in that of extension. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], G II 170), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 4 | |
| A reaction: Presenting this as the place where 'our thought' is 'terminated' seems to place it as mainly having a role in explanation, rather than in speculative metaphysics. |
| 18067 | Abstract objects were a bad way of explaining the structure in mathematics [Kitcher] |
| Full Idea: The original introduction of abstract objects was a bad way of doing justice to the insight that mathematics is concerned with structure. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.1) | |
| A reaction: I'm a fan of explanations in metaphysics, and hence find the concept of 'bad' explanations in metaphysics particularly intriguing. |
| 19379 | The law of the series, which determines future states of a substance, is what individuates it [Leibniz] |
| Full Idea: That there should be a persistent law of the series, which involves the future states of that which we conceive to be the same, is exactly what I say constitutes it as the same substance. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704), quoted by Richard T.W. Arthur - Leibniz 4 'Applying' | |
| A reaction: The 'law of the series' is a bit dubious, but it is reasonable to say that a substance is individuated by its coherent progress of change over time. Disjointed change would imply an absence of substance. The law of the series is called 'primitive force'. |
| 13182 | Changeable accidents are modifications of unchanging essences [Leibniz] |
| Full Idea: Everything accidental or changeable ought to be a modification of something essential or perpetual. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704.06.30) | |
| A reaction: Clear evidence that Leibniz is very much a traditional Aristotelian essentialist, and not as modal logicians tend to characterise him, as a super-essentialist who thinks all properties are essential. They are necessary for identity, but that's different. |
| 13178 | Things in different locations are different because they 'express' those locations [Leibniz] |
| Full Idea: Things that differ in place must express their place, that is, they must express the things surrounding, and thus they must be distinguished not only by place, that is, not by an extrinsic denomination alone, as is commonly thought. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20) | |
| A reaction: This is an unusual view, which has some attractions, as it enables the relations of a thing to individuate it, while maintaining that this is a real difference in character. |
| 19411 | In nature there aren't even two identical straight lines, so no two bodies are alike [Leibniz] |
| Full Idea: In nature any straight line you may take is individually different from any other straight line you may find. Accordingly, it cannot come about that two bodies are perfectly equal and alike. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20) | |
| A reaction: Leibniz was very good at persuasive examples! It remains unclear, though, why he takes the Identity of Indiscernibles to be a necessary truth, when he seems to have only observed it from experience. This is counter to his other principles. |
| 19412 | If two bodies only seem to differ in their position, those different environments will matter [Leibniz] |
| Full Idea: If two bodies differ only in their position, their individual relations to the environment must be taken into account, so that more is involved in their distinguishability than just position. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20) | |
| A reaction: This seems to allow that two bodies could be intrinsically type-identical (though differing in extrinsic features), which is contrary to his normal view. I suppose a different location in the gravitational field will make an intrinsic difference. |
| 12390 | A priori knowledge comes from available a priori warrants that produce truth [Kitcher] |
| Full Idea: X knows a priori that p iff the belief was produced with an a priori warrant, which is a process which is available to X, and this process is a warrant, and it makes p true. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.4) | |
| A reaction: [compression of a formal spelling-out] This is a modified version of Goldman's reliabilism, for a priori knowledge. It sounds a bit circular and uninformative, but it's a start. |
| 12418 | In long mathematical proofs we can't remember the original a priori basis [Kitcher] |
| Full Idea: When we follow long mathematical proofs we lose our a priori warrants for their beginnings. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 02.2) | |
| A reaction: Kitcher says Descartes complains about this problem several times in his 'Regulae'. The problem runs even deeper into all reasoning, if you become sceptical about memory. You have to remember step 1 when you do step 2. |
| 12389 | Knowledge is a priori if the experience giving you the concepts thus gives you the knowledge [Kitcher] |
| Full Idea: Knowledge is independent of experience if any experience which would enable us to acquire the concepts involved would enable us to have the knowledge. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.3) | |
| A reaction: This is the 'conceptualist' view of a priori knowledge, which Kitcher goes on to attack, preferring a 'constructivist' view. The formula here shows that we can't divorce experience entirely from a priori thought. I find conceptualism a congenial view. |
| 12416 | We have some self-knowledge a priori, such as knowledge of our own existence [Kitcher] |
| Full Idea: One can make a powerful case for supposing that some self-knowledge is a priori. At most, if not all, of our waking moments, each of us knows of herself that she exists. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.6) | |
| A reaction: This is a begrudging concession from a strong opponent to the whole notion of a priori knowledge. I suppose if you ask 'what can be known by thought alone?' then truths about thought ought to be fairly good initial candidates. |
| 12413 | A 'warrant' is a process which ensures that a true belief is knowledge [Kitcher] |
| Full Idea: A 'warrant' refers to those processes which produce belief 'in the right way': X knows that p iff p, and X believes that p, and X's belief that p was produced by a process which is a warrant for it. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 01.2) | |
| A reaction: That is, a 'warrant' is a justification which makes a belief acceptable as knowledge. Traditionally, warrants give you certainty (and are, consequently, rather hard to find). I would say, in the modern way, that warrants are agreed by social convention. |
| 20473 | If experiential can defeat a belief, then its justification depends on the defeater's absence [Kitcher, by Casullo] |
| Full Idea: According to Kitcher, if experiential evidence can defeat someone's justification for a belief, then their justification depends on the absence of that experiential evidence. | |
| From: report of Philip Kitcher (The Nature of Mathematical Knowledge [1984], p.89) by Albert Casullo - A Priori Knowledge 2.3 | |
| A reaction: Sounds implausible. There are trillions of possible defeaters for most beliefs, but to say they literally depend on trillions of absences seems a very odd way of seeing the situation |
| 19410 | Scientific truths are supported by mutual agreement, as well as agreement with the phenomena [Leibniz] |
| Full Idea: Among the most powerful indications of truth belongs the fact that scientific propositions agree with one another as well as with phenomena. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1699.03.24/04.03) | |
| A reaction: I take this to be the case not only with science, but with all other truths. Leibniz is particularly keen on the interconnectedness of things, so coherence justification suits him especially well. But surely all scientists embrace this idea? |
| 18075 | Idealisation trades off accuracy for simplicity, in varying degrees [Kitcher] |
| Full Idea: To idealize is to trade accuracy in describing the actual for simplicity of description, and the compromise can sometimes be struck in different ways. | |
| From: Philip Kitcher (The Nature of Mathematical Knowledge [1984], 06.5) | |
| A reaction: There is clearly rather more to idealisation than mere simplicity. A matchstick man is not an ideal man. |
| 13183 | Primitive forces are internal strivings of substances, acting according to their internal laws [Leibniz] |
| Full Idea: Primitive forces can be nothing but the internal strivings [tendentia] of simple substances, striving by means of which they pass from perception to perception in accordance with a certain law of their nature. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704 or 1705) | |
| A reaction: 'Perception' sounds a bit crazy, but he usually qualifies that sort of remark by saying that it is an 'analogy' with conscious willing souls. The 'internal strivings of substances' is a nice phrase for the basic powers in nature where explanations stop. |
| 19409 | Soul represents body, but soul remains unchanged, while body continuously changes [Leibniz] |
| Full Idea: The essence of the soul is to represent bodies. ...The soul and the idea of the body do not signify the same thing. For the soul remains one and the same, while the idea of the body perpetually changes as the body itself changes. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1699.03.24/04.03) | |
| A reaction: This seems to rest on the Cartesian Ego, as the essence of mind which does not change. And yet elsewhere he describes the Ego as a mere abstraction from introspected mental life. |
| 11873 | Our notions may be formed from concepts, but concepts are formed from things [Leibniz] |
| Full Idea: You assert that the notion of substance is formed from concepts, and not from things. But are not concepts themselves formed from things? | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1699.06.23), quoted by David Wiggins - Sameness and Substance Renewed 5.7 | |
| A reaction: A nice remark, which is true even of highly abstruse, abstract or fanciful concepts. You are still left with the question of how far away from reality you have moved when you construct things from your reality-based concepts. |
| 13186 | Universals are just abstractions by concealing some of the circumstances [Leibniz] |
| Full Idea: In forming universals the soul only abstracts certain circumstances by concealing innumerable others. ..A spherical body complete in all respects is nowhere in nature; the soul forms such a notion by concealing aberrations. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704 or 1705) | |
| A reaction: This is Leibniz's affirmation of traditional 'abstraction by ignoring', which everyone seems to have believed in before Frege, and which I personally think is simply correct, even though it is deeply unfashionable and I keep it to myself. |
| 468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
| Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
| From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
| 13185 | Even if extension is impenetrable, this still offers no explanation for motion and its laws [Leibniz] |
| Full Idea: Even if we grant impenetrability is added to extension, nothing complete is brought about, nothing from which a reason for motion, and especially the laws of motion, can be given. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704 or 1705) | |
| A reaction: When it comes to the reasons for the so-called 'laws of nature', scientists give up, because they've only got mathematical descriptions, whereas the philosopher won't give up (even though, embarassingly, the evidence is running a bit thin). |
| 13177 | An entelechy is a law of the series of its event within some entity [Leibniz] |
| Full Idea: I recognize a primitive entelechy in the active force found in motion, something analogous to the soul, whose nature consists in a certain law of the same series of changes. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1699.03.24) | |
| A reaction: This is his 'law-of-the-series', which is a speculative attempt to pin down the character of the active essence of things which gives rise to activity. The law of such activity is within the things themselves, as scientific essentialists claim. |
| 13093 | The only permanence in things, constituting their substance, is a law of continuity [Leibniz] |
| Full Idea: Nothing is permanent in things except the law itself, which involves a continuous succession ...The fact that a certain law persists ...is the very fact that constitutes the same substance. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1704) | |
| A reaction: Aristotle and Leibniz are the very clear ancestors of modern scientific essentialism. I've left out a few inconvenient bits, about containing 'the whole universe', and containing all 'future states'. For Leibniz, laws are entirely rooted in things. |
| 13096 | The force behind motion is like a soul, with its own laws of continual change [Leibniz] |
| Full Idea: I recognise, in the active force which exerts itself through motion, the primitive entelechy or in a word, something analogous to the soul, whose nature consists in a certain perpetual law of the same series of changes through which it runs unhindered. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1699), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 6.1.3 | |
| A reaction: This is a hugely metaphysical account of force, contrasting with Newton's largely mathematical account. He very often says that force is 'analogous' to the soul, rather than that it actually is a soul. He never quite believes that monads are real minds. |
| 13180 | Space is the order of coexisting possibles [Leibniz] |
| Full Idea: Extension is the order of coexisting possibles. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20) | |
| A reaction: [In his next letter he uses the word 'space' instead of 'extension'] This is a rather startling different and modal definition of space. Cf Idea 13181. |
| 13181 | Time is the order of inconsistent possibilities [Leibniz] |
| Full Idea: Time is the order of inconsistent possibilities. | |
| From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1703.06.20) | |
| A reaction: Cf. Idea 13180. This sounds wonderfully bold and interesting, but I can't make much sense of it. One might say it is 'an' order for such things, but 'the' order is weird. |