display all the ideas for this combination of texts
31 ideas
| 8660 | There are potential infinities (never running out), but actual infinity is incoherent [Aristotle, by Friend] |
| Full Idea: Aristotle developed his own distinction between potential infinity (never running out) and actual infinity (there being a collection of an actual infinite number of things, such as places, times, objects). He decided that actual infinity was incoherent. | |
| From: report of Aristotle (works [c.330 BCE]) by Michèle Friend - Introducing the Philosophy of Mathematics 1.3 | |
| A reaction: Friend argues, plausibly, that this won't do, since potential infinity doesn't make much sense if there is not an actual infinity of things to supply the demand. It seems to just illustrate how boggling and uncongenial infinity was to Aristotle. |
| 12058 | Aristotle's matter can become any other kind of matter [Aristotle, by Wiggins] |
| Full Idea: Aristotle's conception of matter permits any kind of matter to become any other kind of matter. | |
| From: report of Aristotle (works [c.330 BCE]) by David Wiggins - Substance 4.11.2 | |
| A reaction: This is obviously crucial background information when we read Aristotle on matter. Our 92+ elements, and fixed fundamental particles, gives a quite different picture. Aristotle would discuss form and matter quite differently now. |
| 6776 | Natural kinds are those that we use in induction [Bird] |
| Full Idea: Natural kinds are the kinds one should make use of in inductive inference (if that is explanation which leads to laws). | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: The problem with this is that it is epistemological rather than ontological. In induction we use superficial resemblences that are immediately obvious, whereas the nature of kinds can be buried deep in the chemistry or physics. |
| 6767 | Rubies and sapphires are both corundum, with traces of metals varying their colours [Bird] |
| Full Idea: Both rubies (valuable) and sapphires (less valuable) are corundum (Al2O3), differing only in their colours, for which traces of iron, titanium and chomium are responsible. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: A nice example which illustrates how natural kinds determined by nominal essence could be drastically different from those suggested by real essence. It certainly suggests that corundum might be a natural kind, but ruby isn't. |
| 6768 | Tin is not one natural kind, but appears to be 21, depending on isotope [Bird] |
| Full Idea: If real essences are decided by microstructure, then what we call the element tin is not a natural kind, but a mixture of 21 different kinds, one for each isotope. There also exist two different allotropes of tin - white tin and grey tin. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: This example vividly brings out the difficulties of the Kripke-Putnam view. If natural kinds 'overlap', then there would be a very extensive overlap among the 21 isotopes of tin. |
| 6770 | Membership of a purely random collection cannot be used as an explanation [Bird] |
| Full Idea: One might randomly collect diverse things and give the collection a name, but one would not expect it to explain anything to say that a certain object belonged to this collection. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: This is in support of Bird's view that natural kinds are formulated because of their explanatory role. There is, though, an undeniable subjective aspect to explanation, in that explanations arise from the ignorance and interests of persons. |
| 6771 | Natural kinds may overlap, or be sub-kinds of one another [Bird] |
| Full Idea: It seems clear that in some cases one natural kind may be a subkind of another, while in other cases natural kinds may overlap without one being the subkind of another. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: Given the enormous difficulty of pinpointing natural kinds (e.g. Idea 6768), it is hard to know whether the comment is correct or not. Ellis says natural kinds come 'in hierarchies', which would make subkinds normal, but overlapping unlikely. |
| 6773 | If F is a universal appearing in a natural law, then Fs form a natural kind [Bird] |
| Full Idea: The proposal is that if F is a universal appearing in some natural law, then Fs form a natural kind. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: Such proposals always invite the question 'What is it about F that enables it to be a universal in a natural law?' Nothing can be ultimately defined simply by its role. The character (essence, even) of the thing makes the role possible. |
| 6769 | In the Kripke-Putnam view only nuclear physicists can know natural kinds [Bird] |
| Full Idea: In the Kripke-Putnam view, it is very difficult for anyone except nuclear physicists to pick out natural kinds, since everything else is made out of compounds of different isotopes. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: The concept of a rigid 'natural kind' does not have to be sacred. Tin might be considered a natural kind, despite having 21 isotopes. What matters is protons, not the neutrons. |
| 6774 | Darwinism suggests that we should have a native ability to detect natural kinds [Bird] |
| Full Idea: Creatures that are able to recognise natural kinds and laws have a selective advantage, so Darwinism suggests that we should have some native ability to detect natural kinds. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: This seems right, but it makes 'natural kind' a rather instrumental concept, relative to our interests. True natural kinds cut across our interests, as when we discover by anatomy that whales are not fish, or that rubies and sapphires are both corundum. |
| 6764 | Nominal essence of a natural kind is the features that make it fit its name [Bird] |
| Full Idea: The nominal essence of a natural kind K consists of those features a thing must have to deserve the name 'a K' by virtue of the meaning of that name. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: Some people think 'nominal essence' is the only essence there is, which would make it relative to human languages. The rival view is that there are 'real essences'. I favour the latter view. |
| 6766 | Jadeite and nephrite are superficially identical, but have different composition [Bird] |
| Full Idea: There might be more than one natural kind that shares the same superficial features, …jade, for example, has two forms, jadeite and nephrite, which are similar in superficial properties, but have different chemical composition and structure. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: It might be questioned whether jadeite and nephrite really are natural kinds, either together or separately. |
| 6808 | Reference to scientific terms is by explanatory role, not by descriptions [Bird] |
| Full Idea: I propose that reference to scientific terms, such as natural kinds and theoretical terms, is not determined by a sense or description attached to the term, but by its explanatory role. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.8) | |
| A reaction: He gives the example of an electron, which had the same role in electrical theory, despite changes in understanding its nature. One might talk of its 'natural' (causal) role, rather than its 'explanatory' role (which implies a human viewpoint). |
| 6753 | Laws are more fundamental in science than causes, and laws will explain causes [Bird] |
| Full Idea: I think laws are fundamental and where there is a cause there is always a set of laws that encompasses the cause; identifying a cause will never be the final word in an scientific investigation, but will be open to supplementation by the underlying law. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.2) | |
| A reaction: I think this is wrong. I would say (from the essentialist angle) that essences have causes, and the laws are the regularities that are caused by the essences. If laws are the lowest level of explanation, why these laws and not others? God? |
| 6762 | Newton's laws cannot be confirmed individually, but only in combinations [Bird] |
| Full Idea: None of Newton's laws individually records anything that can be observed; it is only from combinations of Newton's laws that we can derive the measurable motions of bodies. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.2) | |
| A reaction: This certainly scuppers any traditional positivist approach to how we confirm laws of nature. It invites the possibility that a different combination might fit the same observations. Experiments attempt to isolate laws. |
| 6763 | Parapsychology is mere speculation, because it offers no mechanisms for its working [Bird] |
| Full Idea: Wegener's theory of continental drift was only accepted when the theory of plate tectonics was developed, providing a mechanism. While some correlations exist for parapsychology, lack of plausible mechanisms leaves it as speculation. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.2) | |
| A reaction: But parapsychology is not even on a par with Wegener's speculation, because his was consistent with known physical laws, whereas parapsychology flatly contradicts them. The so-called correlations are also not properly established. |
| 6772 | Existence requires laws, as inertia or gravity are needed for mass or matter [Bird] |
| Full Idea: I suspect that what we mean by 'mass' and 'matter' depends on our identifying the existence of laws of inertia and gravity; hence the idea of a world without laws is incoherent, for there to be anything at all there must be some laws and some kinds. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.3) | |
| A reaction: I find this counterintuitive. Reasonably stable existence requires something reasonably like laws. We only understand the physical world because we interact with it. But neither of those is remotely as strong as Bird's claim. |
| 6740 | 'All uranium lumps are small' is a law, but 'all gold lumps are small' is not [Bird] |
| Full Idea: 'Uranium lumps have mass of less than 1000 kg' is a law, but 'gold lumps have mass of less than 1000kg' is not a law. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: A nice example. Essentialists talk about the nature of the substances; regularity theorists prefer to talk of nested or connected regularities (e.g. about explosions). In induction, how do you decide what your duty requires you to observe? |
| 6741 | There can be remarkable uniformities in nature that are purely coincidental [Bird] |
| Full Idea: Bode's non-law (of 1772, about the gaps between the planets) shows that there can be remarkable uniformities in nature that are purely coincidental. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: If Bode's law really were confirmed, even for asteroids and newly discovered planets, it might suggest that an explanation really is required, and there is some underlying cause. How likely is the coincidence? Perhaps we have no way of telling. |
| 6742 | A law might have no instances, if it was about things that only exist momentarily [Bird] |
| Full Idea: A law might have no instances at all; for example, about the chemical and electrical behaviour of the transuranic elements, which only exist briefly in laboratories. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: Nice example. We need to distinguish, though, (as Bird reminds us) between laws and theories. We have no theories in this area, but there are counterfactual truths about what the transuranic elements would do in certain circumstances. |
| 6743 | If laws are just instances, the law should either have gaps, or join the instances arbitrarily [Bird] |
| Full Idea: For the simple regularity theorist, the function ought to be a gappy one, leaving out values not actually instantiated; …one function would fit the actual points on the graph as well as any other. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: The 'simple' theorist says there is nothing more to a law than its instances. Clearly Bird is right; if the points line up, we join them with a straight line, making counterfactual assumptions about points which were not actually observed. |
| 6744 | Where is the regularity in a law predicting nuclear decay? [Bird] |
| Full Idea: If a law of nuclear physics says that nuclei of a certain kind have a probability p of decaying within time t, what is the regularity here? | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: Hume gives an answer, in terms of regularities observed among previous instances. Nevertheless the figure p given in the law does not itself have any instances, so the law is predicting something that may never have actually happened before. |
| 6747 | Laws cannot explain instances if they are regularities, as something can't explain itself [Bird] |
| Full Idea: It can be objected that laws cannot do the job of explaining their instances if they are merely regularities, ...because something cannot explain itself. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: A nice point. The objection assumes that a law should explain things, rather than just describing them. I take the model to be smoking-and-cancer; the statistics describe what is happening, but only lung biochemistry will explain it. |
| 6748 | Similar appearance of siblings is a regularity, but shared parents is what links them [Bird] |
| Full Idea: There may be a regularity of siblings looking similar, but the tie that binds them is not their similarity, but rather their being born of the same parents. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: A nice objection to the regularity view. Regularities, as so often in philosophy (e.g. Idea 1364), may be the evidence or test for a law, rather than the law itself, which requires causal mechanisms, ultimately based (I think) in essences. |
| 6749 | We can only infer a true regularity if something binds the instances together [Bird] |
| Full Idea: We cannot infer a regularity from its instances unless there is something stronger than the regularity itself binding the instances together. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: Spells out the implication of the example in Idea 6748. The reply to this criticism would be that no account can possibly be given of the 'something stronger' than further regularities, at a lower level (e.g. in the physics). |
| 6803 | If we only infer laws from regularities among observations, we can't infer unobservable entities. [Bird] |
| Full Idea: If the naïve inductivist says we should see well-established regularities among our observations, and take that to be the law or causal connection…this will not help us to infer the existence of unobservable entities. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.8) | |
| A reaction: The obvious solution to this difficulty is an appeal to 'best explanation'. Bird is obviously right that we couldn't survive in the world, let alone do science, if we only acted on what we had actually observed (e.g. many bodies, but not the poison). |
| 6801 | Accidental regularities are not laws, and an apparent regularity may not be actual [Bird] |
| Full Idea: Many actual regularities are not laws (accidental regularities), and many perceived regularities are not actual ones (a summer's worth of observing green leaves). | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.8) | |
| A reaction: These problems are not sufficient to refute the regularity view of laws. Accidental regularities can only be short-lived, and perceived regularities support laws without clinching them. There is an awful lot of regularity behind laws concerning gravity. |
| 6746 | There may be many laws, each with only a few instances [Bird] |
| Full Idea: It might be that there is a large number of laws each of which has only a small number of instances. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: This is a problem for the Ramsey-Lewis view (Idea 6745) that the laws of nature are a simple, powerful and coherent system. We must be cautious about bringing a priori principles like Ockham's Razor (Idea 3667) to bear on the laws of nature. |
| 6745 | A regularity is only a law if it is part of a complete system which is simple and strong [Bird] |
| Full Idea: The systematic (Ramsey-Lewis) regularity theory says that a regularity is a law of nature if and only if it appears as a theorem or axiom in that true deductive system which achieves a best combination of simplicity and strength. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.1) | |
| A reaction: Personally I don't accept the regularity view of laws, but this looks like the best account anyone has come up with. Individual bunches of regularities can't add up to or demonstrate a law, but coherence with all regularities might do it. |
| 6802 | With strange enough predicates, anything could be made out to be a regularity [Bird] |
| Full Idea: We learned from Goodman's problem that with strange enough predicates anything could be made out to be a regularity. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.8) | |
| A reaction: For Goodman's problem, see Idea 4783. The point, as I see it, is that while predicates can be applied arbitrarily (because they are just linguistic), properties cannot, because they are features of the world. Emeralds are green. |
| 6789 | If flame colour is characteristic of a metal, that is an empirical claim needing justification [Bird] |
| Full Idea: I might say that flame colours are a characteristic feature of metals, but this is an empirical proposition which is in part about the unobserved, and stands in need of justification. | |
| From: Alexander Bird (Philosophy of Science [1998], Ch.5) | |
| A reaction: This draws attention to the fact that essentialism is not just a metaphysical theory, but is also part of the scientific enterprise. Among things to research about metals is the reason why they have a characteristic flame. |