| 16646 | To understand a triangle summing to two right angles, we need to know the essence of a line [Aristotle] |
| Full Idea: In mathematics it is useful for the understanding of the property of the equality of the interior angles of a triangle to two right angles to know the essential nature of the straight and the curved or of the line and the plane. | |
| From: Aristotle (De Anima [c.329 BCE], 402b18) | |
| A reaction: Although Aristotle was cautious about this, he clearly endorses here the idea that essences play an explanatory role in geometry. The caution is in the word 'useful', rather than 'vital'. How else can we arrive at this result, though? |
| 15119 | Aristotelian explanation by essence may need to draw on knowledge of other essences [Aristotle, by Koslicki] |
| Full Idea: From Aristotle's biology we learn that a successful scientific explanation of the necessary (but non-essential) features of one type of phenomenon (e.g. camels) my require appeal to facts about the essences of other types of phenomena (stomachs). | |
| From: report of Aristotle (The History of Animals [c.344 BCE]) by Kathrin Koslicki - Essence, Necessity and Explanation 13.4 |
| 11384 | We know something when we fully know what it is, not just its quality, quantity or location [Aristotle] |
| Full Idea: It is when we know what a man is or what fire is that we reckon that we know a particular item in the fullest sense, rather than when we merely know its quality, quantity or location. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1028a36) | |
| A reaction: The word 'what' should usually be taken to indicate that Aristotle is talking about essence (as V. Politis confirms of this passage). This idea is a key one for the claim that Aristotelian essences are essentially (sic) explanatory. |
| 16105 | We know a thing when we grasp its essence [Aristotle] |
| Full Idea: We have knowledge of each thing when we grasp the what-it-was-to-be [to ti en einai] that thing. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1031b08) | |
| A reaction: This is a key remark in my understanding of the whole business of essentialism. It really concerns the way in which we are able to grasp reality, rather than how it is in itself. It is not mere convention, because the grasping responds to the reality. |
| 16135 | Real enquiries seek causes, and causes are essences [Aristotle] |
| Full Idea: Real enquiries stand revealed as causal enquiries (and the cause is the what-it-was-to-be-that-thing [to ti en einai]). | |
| From: Aristotle (Metaphysics [c.324 BCE], 1041a28) | |
| A reaction: As good a quotation as any for showing that Aristotelian essences exist entirely by their role in explanation. |
| 11296 | The explanation is what gives matter its state, which is the form, which is the substance [Aristotle] |
| Full Idea: The explanation [aition - cause] that is the object of enquiry is that by virtue of which the matter is in the state that it is in. And this cause [explanation] is the form, and the form the substance [ousia]. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1041b08) | |
| A reaction: A key sentence, I think, for understanding Aristotle's whole enterprise. The explanation is the essence; the essence is what explains. |
| 11999 | Essential properties explain in conjunction with properties shared by the same kind [Aristotle, by Kung] |
| Full Idea: Aristotle makes it clear that properties which belong essentially to anything have explanatory power vis-à-vis the other properties of things of that kind. | |
| From: report of Aristotle (Metaphysics [c.324 BCE], props) by Joan Kung - Aristotle on Essence and Explanation IV | |
| A reaction: This means that explanation will always occur at the level of generalisation, leading to what we call 'laws', but some events are only explicable at the level of the individual. |
| 22524 | The nature of each thing is its mature state [Aristotle] |
| Full Idea: What each thing is when its coming to be has been complete, this we say is the nature of each - for example, of a human, or of a horse, or of a household. | |
| From: Aristotle (Politics [c.332 BCE], 1252b32) | |
| A reaction: This works better for animate than for inanimate things. Aristotle is much clearer when we talk of the 'nature' of each thing, rather than its 'essence', because the latter has been blurred. I like 'essential nature'. |
| 12000 | Aristotle regularly says that essential properties explain other significant properties [Aristotle, by Kung] |
| Full Idea: The view that essential properties are those in virtue of which other significant properties of the subjects under investigation can be explained is encountered repeatedly in Aristotle's work. | |
| From: report of Aristotle (works [c.330 BCE]) by Joan Kung - Aristotle on Essence and Explanation IV | |
| A reaction: What does 'significant' mean here? I take it that the significant properties are the ones which explain the role, function and powers of the object. |
| 11198 | Definition of essence makes things understandable [Aquinas] |
| Full Idea: It is definition of essence that makes things understandable. | |
| From: Thomas Aquinas (De Ente et Essentia (Being and Essence) [1267], p.92) | |
| A reaction: The aim of philosophy is understanding, which is achieved by successful explanation. I totally agree with this Aristotelian view, so neatly summarised by Aquinas. |
| 16784 | Forms make things distinct and explain the properties, by pure form, or arrangement of parts [Arnauld,A/Nicole,P] |
| Full Idea: The form is what renders a thing such and distinguishes it from others, whether it is a being really distinct from the matter, according to the Schools, or whether it is only the arrangement of the parts. By this form one must explain its properties. | |
| From: Arnauld / Nicole (Logic (Port-Royal Art of Thinking) [1662], III.18 p240), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 27.6 | |
| A reaction: If we ask 'what explains the properties of this thing' it is hard to avoid coming up with something that might be called the 'form'. Note that they allow either substantial or corpuscularian forms. It is hard to disagree with the idea. |
| 13073 | To understand the properties we must know the essence, as with a circle [Spinoza] |
| Full Idea: If a circle is defined as a figure in which lines from centre to circumference are equal, such definitions do not explain the essence of a circle, but only a property. The properties of a thing are not understood as long as their essences are not known. | |
| From: Baruch de Spinoza (Improvement of Understanding [1675], §95), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 1.2.1 | |
| A reaction: This is the traditional Aristotelian view of essence, and the example of a circle is nice, though I am not sure what the essence of a circle might be. Presumably ALL the properties of a circle must flow from it. |
| 17026 | From the phenomena, I can't deduce the reason for the properties of gravity [Newton] |
| Full Idea: I have not as yet been able to deduce from the phenomena the reason for the properties of gravity. | |
| From: Isaac Newton (Principia Mathematica [1687], Bk 3 Gen Schol) | |
| A reaction: I take it that giving the reasons for the properties of gravity would be an essentialist explanation. I am struck by the fact that the recent discovery of the Higgs Boson appears to give us a reason why things have mass (i.e. what causes mass). |
| 16037 | Locke seems to use real essence for scientific explanation, and substratum for the being of a thing [Locke, by Jones,J-E] |
| Full Idea: It seems that Locke employs the concept of a real essence when he is addressing issues of scientific explanation, and he appeals to substratum when he is discussing the general concept of what it is to be a thing (as opposed to a property or mode). | |
| From: report of John Locke (Essay Conc Human Understanding (2nd Ed) [1694]) by Jan-Erik Jones - Real Essence §4.4 | |
| A reaction: [This idea is attributed to Nicholas Jolley 1999] Locke was, of course, utterly pessimistic about the possibility of knowing real essences. For Aristotle, real essence does both jobs. |
| 16032 | To explain qualities, Locke invokes primary and secondary qualities, not real essences [Locke, by Jones,J-E] |
| Full Idea: When criticising the scholastic account of the explanation of qualities, Locke typically refrains from invoking real essences, and instead talks about primary, secondary and tertiary qualities. | |
| From: report of John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.08.10-26) by Jan-Erik Jones - Real Essence §2 | |
| A reaction: This is the good empiricists' response to attempts to explain by means of essences - that we must stick to what is 'nearer the surface' and more knowable, only distinguishing which bits match the reality of the object. |
| 12519 | Gold is supposed to have a real essence, from whence its detectable properties flow [Locke] |
| Full Idea: The ring on my finger is supposed to have a real essence, whereby it is gold, from whence those qualities flow which I find in it, viz. its colour, weight, hardness, fusibility, fixedness, and change of colour upon a slight touch of mercury, etc. | |
| From: John Locke (Essay Conc Human Understanding (2nd Ed) [1694], 2.31.06) | |
| A reaction: This is Locke's notion of essence, as simply the underlying cause of the detectable properties. Oderberg says real essences are not hidden, but are the macro-features we all know gold to have. Locke never denies real essences. |
| 12977 | We will only connect our various definitions of gold when we understand it more deeply [Leibniz] |
| Full Idea: We can define gold as the heaviest metal, or by assaying procedures, but only when men have penetrated more deeply into the nature of things will they be able to see why one belongs with the other. | |
| From: Gottfried Leibniz (New Essays on Human Understanding [1704], 2.31) | |
| A reaction: He mentions that geometry is different, because we do have perfect ideas of things. This is part of Leibniz's optimism about the future of science, in comparison with the surprising pessimism of the empiricists. See Idea 12976 and Idea 12975. |
| 12729 | The cause of a change is not the real influence, but whatever gives a reason for the change [Leibniz] |
| Full Idea: That thing from whose state a reason for the changes is most readily provided is adjudged to be the cause. ...Causes are not derived from a real influence, but from the providing of a reason. | |
| From: Gottfried Leibniz (Specimen inventorum [1689], A6.4.1620), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 5 | |
| A reaction: Leibniz is not denying that there are real influences. He seems to be offering the thesis which I am pursuing, that the need for explanation is the crucial factor in shaping the structure of our metaphysics. |
| 13089 | To fully conceive the subject is to explain the resulting predicates and events [Leibniz] |
| Full Idea: Even in the most contingent truths, there is always something to be conceived in the subject which serves to explain why this predicate or event pertains to it, or why this has happened rather than not. | |
| From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.06) | |
| A reaction: The last bit, about containing what has happened, seems absurd, but the rest of it makes sense. It is just the Aristotelian essentialist view, that a full understanding of the inner subject will both explain and predict the surface properties. |
| 13092 | The essence of substance is the law of its changes, as in the series of numbers [Leibniz] |
| Full Idea: The essence of substance consists in ...the law of the sequence of changes, as in the nature of the series in numbers. | |
| From: Gottfried Leibniz (works [1690], A 6.3.326), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 6.1.2 | |
| A reaction: Thus we might say, in this spirit, that the essence of number is the successor operation, as defined by Dedekind and Peano (and perhaps their amenability to inductive proof). I like this. Metaphysicians rule - they penetrate the heart of nature. |
| 13569 | To give essentialist explanations there have to be natural kinds [Ellis] |
| Full Idea: There can be no essentialist explanations constructed in any field where the subject matter is not naturally divided into kinds. | |
| From: Brian Ellis (Scientific Essentialism [2001], Intro) | |
| A reaction: A crux. I like individual essences, such as the character of a particular person. However, Ellis may be right, since while we may identify an individual essence as the source of a behaviour, we may not then be able to give any 'explanation'. |
| 15975 | Can the qualities of a body be split into two groups, where the smaller explains the larger? [Alexander,P] |
| Full Idea: Is there any way of separating the qualities that bodies appear to have into two groups, one as small as possible and the other as large as possible, such that the smaller group can plausibly be used to explain the larger? | |
| From: Peter Alexander (Ideas, Qualities and Corpuscles [1985], 5.02) | |
| A reaction: Alexander implies that this is a question Locke asked himself. This is pretty close to what I take to be the main question for essentialism, though I am cautious about couching it in terms of groups of qualities. I think this was Aristotle's question. |
| 15219 | Essence explains passive capacities as well as active powers [Harré/Madden] |
| Full Idea: Capacities just as much as powers, what particulars and substances are liable to undergo as well as what they are able to do, are explained by reference to what the thing is in itself. | |
| From: Harré,R./Madden,E.H. (Causal Powers [1975], 1.II.C) | |
| A reaction: This is an important warning against trying to give the whole account in terms of powers - unless the capacities and structures and categorical properties can also be explained in terms of the basic powers. |
| 11995 | Some peripheral properties are explained by essential ones, but don't themselves explain properties [Kung] |
| Full Idea: There will be demonstrated properties at the edge of the system, so to speak. They will be explained in terms of the essential properties of the basic entities and principles of the science, but will themselves not be explanatory of further properties. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: This is an important line of thought which needs clarification. We can't glibly say that essences are what explain the other properties. Some properties do more than others to explain subsequent dependent properties. |
| 11996 | Some non-essential properties may explain more than essential-but-peripheral ones do [Kung] |
| Full Idea: It seems highly likely that some non-essential properties may explain more about the individual or about things of his kind than the peripheral properties. | |
| From: Joan Kung (Aristotle on Essence and Explanation [1977], II) | |
| A reaction: Another important issue, if one is defending the explanatory role of essences. It is not only essences which explain. A key question is whether we endorse individual essences as well as generic ones. I think we should. They explain the details. |
| 11848 | Asking 'what is it?' nicely points us to the persistence of a continuing entity [Wiggins] |
| Full Idea: The special effectiveness of the 'what is it?' question is that, in the case of continuants, it refers us back to our constantly exercised idea of the persistence and life-span of an entity. | |
| From: David Wiggins (Sameness and Substance Renewed [2001], 2.2) | |
| A reaction: Compare 'this is a human' with 'this is a member of a family noted for its longevity'. We can't simply answer 'what is it?' by tossing it into the nearest category. I say we need an individual essence for explanation, not just a sortal. |
| 12064 | The category of substance is more important for epistemology than for ontology [Wiggins] |
| Full Idea: For us the importance of the category of substance, if it has any importance, is not so much ontological as relative to our epistemological circumstances and the conditions under which we have to undertake inquiry. | |
| From: David Wiggins (Substance [1995], 4.13.2) | |
| A reaction: This seems to be a rather significant concession. Wiggins has revived the notion of substance in recent times, but he is not quite adding it to the furniture of the world. Personally I increasingly think we can dump it, in ontology and epistemology. |
| 12049 | Naming the secondary substance provides a mass of general information [Wiggins] |
| Full Idea: Answering 'what is it?' with the secondary substance identifies an object with a class of continuants which survive certain changes, come into being in certain ways, are qualified in certain ways, behave in certain ways, and cease to be in certain ways. | |
| From: David Wiggins (Substance [1995], 4.3.3) | |
| A reaction: Thus the priority of this sort of answer is that a huge range of explanations immediately flow from it. I take the explanation to be prior, and the primary substance to be prior, since secondary substance is inductively derived from it. |
| 14322 | If fragile just means 'breaks when dropped', it won't explain a breakage [Mumford] |
| Full Idea: If fragile means nothing more than 'breaks when dropped', then it is no explanation of why something breaks when dropped. | |
| From: Stephen Mumford (Dispositions [1998], 06.5) | |
| A reaction: His point is that you have to unpack the notion of fragile, which presumably cites underlying mechanisms. This is the 'virtus dormitiva' problem - but that explanation of opium's dormitive powers is not entirely stupid. |
| 17481 | Nuclear charge (plus laws) explains electron structure and spectrum, but not vice versa [Hendry] |
| Full Idea: Given relevant laws of nature (quantum mechanics, the exclusion principle) nuclear charge determines and explains electronic structure and spectroscopic behaviour, but not vice versa. | |
| From: Robin F. Hendry (Chemistry [2008], 'Micro') | |
| A reaction: I argue that the first necessary condition for essentialism is a direction of explanation, and here we seem to have one. |
| 11905 | Locke's kind essences are explanatory, without being necessary to the kind [Mackie,P] |
| Full Idea: One might speak of 'Lockean real essences' of a natural kind, a set of properties that is basic in the explanation of the other properties of the kind, without commitment to the essence belonging to the kind in all possible worlds. | |
| From: Penelope Mackie (How Things Might Have Been [2006], 10.1) | |
| A reaction: I think this may be the most promising account. The essence of a tiger explains what tigers are like, but tigers may evolve into domestic pets. Questions of individuation and of explaining seem to be quite separate. |
| 15114 | Discovering the Aristotelian essence of thunder will tell us why thunder occurs [Koslicki] |
| Full Idea: Both the question 'what is thunder?', and the question 'why does thunder occur?', for Aristotle, are answered simultaneously, once it has been discovered what the essence of thunder it, i.e. what it is to be thunder. | |
| From: Kathrin Koslicki (Essence, Necessity and Explanation [2012], 13.3.1 n10) | |
| A reaction: I take this idea to be pretty much the whole story about essences. |
| 15710 | Bohr explained the periodic table and chemical properties of elements, using the quantum atom [Kumar] |
| Full Idea: Bohr used the quantum atom to explain the periodic table and the chemical properties of the elements. ...It was his new theory about the arrangement of electrons inside atoms that explained the placing and grouping of elements in the periodic table. | |
| From: Manjit Kumar (Quantum: Einstein and Bohr [2008], Ch 04) | |
| A reaction: (second sentence p.133) This is Exhibit A for the idea that essences are explanatory, and are discovered by scientists. The moot point would be whether it is appropriate to describe electron shells as part of the 'essence' of an atom. |
| 16783 | Essences must explain, so we can infer them causally from the accidents [Pasnau] |
| Full Idea: Without the explanatory role of essence, the underlying epistemic picture would be jeopardised, because there would no longer be any causal route by which we might get from accidents to essence. | |
| From: Robert Pasnau (Metaphysical Themes 1274-1671 [2011], 27.5) | |
| A reaction: There is a slight whiff of circularity here. It could be that we are psychologically desperate for essences, and so we invent bogus causal routes from the accidents to get at them. Can we know there are essences awaiting us, on independent grounds? |
| 16975 | Essences are used to explain natural kinds, modality, and causal powers [Tahko] |
| Full Idea: Essences are supposed to do a lot of explanatory work: natural kinds can be identified in terms of their essences, metaphysical modality can be reduced to essence, the causal power of objects can be explained with the help of essence. | |
| From: Tuomas E. Tahko (The Epistemology of Essence (draft) [2013], 1) | |
| A reaction: Natural kinds and modality are OK with me, but I'm dubious about the third one. If an essence explains something's causal powers, I have no idea what an essence might be. Essence are largely characterised in terms of causal powers. |