Combining Philosophers

Ideas for Peter Geach, Gottfried Leibniz and Aristotle

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69 ideas

9. Objects / D. Essence of Objects / 1. Essences of Objects
Aristotelian essence underlies behaviour, or underlies definition, or is the source of existence [Aristotle, by Aquinas]
     Full Idea: Aristotle calls a substance a nature. This expresses essence as what underlies a thing's characteristic behaviour, whereas whatness expresses it as underlying the definition, and essence refers to it as that through which and in which it has existence.
     From: report of Aristotle (Metaphysics [c.324 BCE]) by Thomas Aquinas - De Ente et Essentia (Being and Essence) p.92
     A reaction: I don't really understand the third one, unless it is what gives something its identity, which probably then reduces to the second one. The big choice is between essence explaining behaviour and essence explaining definition. Interesting.
Aristotelian essence is retained with identity through change, and bases our scientific knowledge [Aristotle, by Copi]
     Full Idea: For Aristotle, the essential properties of an object are those which are retained by it during any change through which the object remains identifiable; and they are the properties which are most important in our scientific knowledge of it.
     From: report of Aristotle (Metaphysics [c.324 BCE]) by Irving M. Copi - Essence and Accident p.712
     A reaction: This pioneering thought of Copi's (at least, he was a pioneer in that he read Aristotle properly) strikes me as the key to understanding the concept of essence.
Aristotle says changing, material things (and not just universals) have an essence [Aristotle, by Politis]
     Full Idea: Aristotle wanted to argue (against Plato) that changing, material things, and not only universals that are true of them, have an essence.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Vassilis Politis - Aristotle and the Metaphysics 7.5
     A reaction: This is the huge idea which Aristotle contributes to our understanding of the world, and which I take to be one of the most important ideas in philosophy (though I accept that defending essences is a little precarious).
Are essences actually universals? [Aristotle, by Politis]
     Full Idea: Some critics say that Aristotle conceives of essences as universals.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Vassilis Politis - Aristotle and the Metaphysics 7.5
     A reaction: [He cites M.Woods for this view] Politis opposes this view of Aristotle, and I think I do (with limited scholarship!). It seems to be an unorthodox view when discussing Aristotelian essences, but a very common view when discussing properties.
The essence of a circle is the equality of its radii [Leibniz]
     Full Idea: The essence of a circle consists in the equality of all lines drawn from its centre to its circumference.
     From: Gottfried Leibniz (Letters to Thomasius [1669], 1669)
     A reaction: Compare Locke in Idea 13431 and Spinoza in Idea 13073 on the essence of geometrical figures. A key question is whether the essence is in the simplest definition, or in a complex and wide-ranging account, e.g. including conic sections for circles.
Subjects include predicates, so full understanding of subjects reveals all the predicates [Leibniz]
     Full Idea: The subject-term must always include the predicate-term, in such a way that the man who understood the notion of the subject perfectly would also judge that the predicate belongs to it.
     From: Gottfried Leibniz (Discourse on Metaphysics [1686], §8)
     A reaction: Sounds as if every sentence is analytic, but he doesn't mean that. He does, oddly, mean that if we fully understand the name 'Alexander', we understand his complete history, which is a bit silly, I'm afraid. Even God doesn't learn things just from names.
Basic predicates give the complete concept, which then predicts all of the actions [Leibniz]
     Full Idea: Apart from those that depend on others, one must only consider together all the basic predicates in order to form the complete concept of Adam adequate to deduce from it everything that is ever to happen to him, as much as is necessary to account for it.
     From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.06)
     A reaction: This (implausibly) goes beyond mere prediction of properties. Eve's essence seems to be relevant to Adam's life. Note that the complete concept is not every predicate, but only those 'necessary' to predict the events. Cf Idea 13082.
Essences exist in the divine understanding [Leibniz]
     Full Idea: Essences exist in the divine understanding before one considers will.
     From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 X)
     A reaction: This is a sort of religious neo-platonism. The great dream seems to be that of mind-reading God, and the result is either Pythagoras (it's numbers!), or Plato (it's pure ideas!), or this (it's essences!). See D.H.Lawrence's poem on geranium and mignottes.
A true being must (unlike a chain) have united parts, with a substantial form as its subject [Leibniz]
     Full Idea: In a Being one per se a real union is required consisting not in the situation or motion of parts, as in a chain or a house, but in a unique individual principle and subject of attributes and operations, in us a soul and in a body a substantial form.
     From: Gottfried Leibniz (De Mundo Praesenti [1686], A6.4.1506), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 7
     A reaction: Leibniz is said not to be an essentialist, by making all properties essential, but he is certainly committed to substance, and it sounds like essence here (or one view of essence), when it makes identity possible. This idea is pure Aristotle.
9. Objects / D. Essence of Objects / 2. Types of Essence
Aristotelian essences are causal, not classificatory [Aristotle, by Witt]
     Full Idea: The primary role of essences in Aristotle's theory of substance is causal, rather than classificatory.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Charlotte Witt - Substance and Essence in Aristotle 5.4
     A reaction: This is the nicest summary of the view which I wish to champion. Classification results from patterns of causation, just as laws of nature result from regularities in the behaviour of causal powers.
9. Objects / D. Essence of Objects / 3. Individual Essences
The essence of a single thing is the essence of a particular [Aristotle]
     Full Idea: The what-it-was-to-be-that-thing [to ti en einai] for a single thing is what-it-was-to-be-that-thing for a particular.
     From: Aristotle (Metaphysics [c.324 BCE], 1054a16)
     A reaction: This seems to give clear support for the view I favour, that Aristotle believes in individual essences, and not just generic kinds.
A primary substance reveals a 'this', which is an individual unit [Aristotle]
     Full Idea: Every substance seems to signify a certain 'this'. As regards the primary substances, it is indisputably true that each of them signifies a certain 'this'; for the thing revealed is individual and numerically one.
     From: Aristotle (Categories [c.331 BCE], 03b10)
     A reaction: The notion of 'primary' substance is confined to this earlier metaphysics of Aristotle.
Particulars are not definable, because they fluctuate [Aristotle]
     Full Idea: Particular perceptible substances are excluded from definition. ...An object that admits of being in a variety of states is an object of opinion, and thus incontrovertibly not of definition.
     From: Aristotle (Metaphysics [c.324 BCE], 1039b30)
     A reaction: This more or less demolishes my original reading of Aristotle, so back to the drawing board. We need to revise Aristotle. He says differentiae home in the individual but never get there. I (now) say cross-referencing of universals gets you there.
Essence is the cause of individual substance, and creates its unity [Aristotle, by Witt]
     Full Idea: Aristotle describes form or essence as the cause of there being an actual individual substance, and as the cause of its being a unity rather than a heap.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Charlotte Witt - Substance and Essence in Aristotle Intro
     A reaction: Wiggins defends the species-essence view (Idea 12068) by preferring the 'secondary substance' account in 'Categories' to Aristotle's ideas about 'form' which emerge later in 'Metaphysics'. I prefer Witt to Wiggins.
Individual essences are not universals, since those can't be substances, or cause them [Aristotle, by Witt]
     Full Idea: For Aristotle the essences of individual substances are individual rather than universal, ...since nothing universal can be a substance, nor can it be a principle or cause of a substance.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Charlotte Witt - Substance and Essence in Aristotle Intro
     A reaction: This is the second of Witt's three theses which she offers in opposition to the orthodox interpretation of Aristotle, and again I think she is right.
Aristotelian essence is not universal properties, but individual essence [Aristotle, by Witt]
     Full Idea: We should replace the traditional interpretation of Aristotelian essences - as clusters of universal properties - with an interpretation according to which an essence is an individual substance, though not a composite or sensible substance.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Charlotte Witt - Substance and Essence in Aristotle 5
     A reaction: I get the impression that this is a growing view amongst Aristotle scholars, which really ruins a widespread view which I associate with Wiggins, that essences are to do with categories, sortals and kinds. I associate essences with explanations.
Aristotle does not accept individual essences; essential properties are always general [Aristotle, by Kung]
     Full Idea: Aristotle does not label 'essential' what are now called 'individual essences'. The properties which belong essentially to an individual are always general properties, capable of belonging to more than one thing.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Joan Kung - Aristotle on Essence and Explanation IV
     A reaction: [She offers four references from 'Metaphysics' in support] I think I want to disagree with Aristotle on this one (gulp). Thus his essential properties are one-over-many - his version of universals. I say individuals explain universals, and are prior.
Aristotle's essence explains the existence of an individual substance, not its properties [Aristotle, by Witt]
     Full Idea: Aristotle's notion of form or essence is meant to explain why there is an individual substance there at all, not what features constitute the identity of a given individual substance within a domain of individual substances.
     From: report of Aristotle (Metaphysics [c.324 BCE], hylom) by Charlotte Witt - Substance and Essence in Aristotle 4.4
     A reaction: I begin to think that the notion of 'essence' is extremely useful in aiding our grasp of reality, but the notion of 'substance' is not. We can just talk of 'identity', without implying some stuff that constitutes that identity. Essence is powers.
Aristotle takes essence and form as a particular, not (as some claim) as a universal, the species [Aristotle, by Politis]
     Full Idea: It seems that Aristotle thinks that the essence and the form is a particular, ...though a very different interpretation argues that, for Aristotle, the essence and form of a changing, material thing is a universal, namely the species of the thing.
     From: report of Aristotle (Metaphysics [c.324 BCE], partic) by Vassilis Politis - Aristotle and the Metaphysics 7.5
     A reaction: I am fairly thoroughly persuaded that Politis's view (the first half of this idea) is the correct interpretation, and it is certainly the one I find more congenial. The second one I associate with the erroneous idea of sortal essentialism, as in Wiggins.
To be a subject a thing must be specifiable, with some essential properties [Aristotle, by Gill,ML]
     Full Idea: Aristotle shows that, for something to be a subject at all, it must be specifiable as something in itself, with essential properties that are mentioned in its defining account, since no subject can be the bearer of accidental properties alone.
     From: report of Aristotle (Metaphysics [c.324 BCE], Z.3) by Mary Louise Gill - Aristotle on Substance Ch.2
     A reaction: This is Aristotle supporting the very modern necessary-properties view of essentialism. Notice that it emerges from being 'specifiable' - that is, from Aristotle's requirement that a logos and definition be available. He rejects bare particulars.
Particular truths are just instances of general truths [Leibniz]
     Full Idea: The reasons for particular truths rest wholly on the more general ones of which they are mere instances.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 1.01)
     A reaction: Clearly particulars have their own distinctive truth, but the Leibniz case seems to be that a particular is a unique intersection for an array of general truths - and nothing else. Audrey Hepburn's smile has no generalities to it.
We can't know individuals, or determine their exact individuality [Leibniz]
     Full Idea: It is impossible for us to have knowledge of individuals and to find the means of determining exactly the individuality of everything.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.3)
     A reaction: Aristotle was clearly also tempted by this doubt (since universals are involved), though individuals are what he wanted to understand. I think they are wrong. Leibniz gives the bizarre reason that we can't know individuals as they each contain infinity.
Everything that is has one single essence [Aristotle]
     Full Idea: Everything that is has one single essence [en esti to einai].
     From: Aristotle (Topics [c.331 BCE], 141a36)
     A reaction: Does this include vague objects, and abstract 'objects'? Sceptics might ask what grounds this claim. Does Dr Jeckyll have two essences?
9. Objects / D. Essence of Objects / 4. Essence as Definition
A thing's essence is what is mentioned in its definition [Aristotle, by Lawson-Tancred]
     Full Idea: Aristotle believes that the essence of a thing is those per se features of it that are mentioned in a definition.
     From: report of Aristotle (Metaphysics [c.324 BCE], 1030a02) by Hugh Lawson-Tancred - Introductions to 'Metaphysics' p.177
     A reaction: Compare Idea 11291.
Essence is what is stated in the definition [Aristotle, by Politis]
     Full Idea: For Aristotle, the essence of a thing is what is stated in the definition of that thing.
     From: report of Aristotle (Metaphysics [c.324 BCE], defs) by Vassilis Politis - Aristotle and the Metaphysics 7.5
Definitions recognise essences, so are not themselves essences [Aristotle]
     Full Idea: If a definition is the recognition of some essence, it is clear that such items are not essences.
     From: Aristotle (Posterior Analytics [c.327 BCE], 90b17)
     A reaction: So definitions are not themselves essences (as some modern thinkers claim). The idea seems obvious to me, but it is a warning against a simplistic view of Aristotelian essences, and a reminder that such things are real, not verbal.
If definition is of universals, many individuals have no definition, and hence no essence [Aristotle, by Witt]
     Full Idea: If definition is of the universal rather than of the particular, ...it begins to appear that individual material substances do not have definitions and, hence, do not have essences at all.
     From: report of Aristotle (Metaphysics [c.324 BCE], partic) by Charlotte Witt - Substance and Essence in Aristotle 5.1
     A reaction: This is a very challenging claim against my own defence (and Witt's) of individual essences. In switching to individual essences, one has to make them unstable and variable, and lacking necessity, and hence maybe not essential.
Essence is just the possibility of a thing [Leibniz]
     Full Idea: Essence is fundamentally nothing but the possibility of the thing under consideration. Something which is thought possible is expressed by a definition.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.03)
     A reaction: It is unclear whether he means 'possible modes of existence' or 'possible actions of the thing'. Leibniz sees more clearly than Aristotle that essences extend beyond the actual thing, because Leibniz is more aware of the active powers.
Things have an essence if their explanation is a definition [Aristotle]
     Full Idea: A what-it-was to-be-that-thing only belongs to those things for whom an account just is a definition.
     From: Aristotle (Metaphysics [c.324 BCE], 1030a06)
     A reaction: That seems to be that 'to ti en einai' (aka essence) only has a 'logos' if it has a 'horismos'. It seems that having a definition as its account is a necessary condition for an essence, but not sufficient. It looks to me as if essence must be explanatory.
9. Objects / D. Essence of Objects / 5. Essence as Kind
The Aristotelian view is that the essential properties are those that sort an object [Aristotle, by Marcus (Barcan)]
     Full Idea: The Aristotelian view is that essential properties sort entities in some fashion. ...Being an entity, or being self-identical, or being a unity, fail to sort Socrates from anything else, but being identical with Socrates sorted him from everything.
     From: report of Aristotle (Metaphysics [c.324 BCE], props) by Ruth Barcan Marcus - Essential Attribution p.196
     A reaction: [She cites Daniel Bennett 1969 for this] This doesn't feel right. I take it that sorting things is posterior to discovering that they have different causal powers, as with H2O and XYZ, or jadeite and nephrite.
9. Objects / D. Essence of Objects / 6. Essence as Unifier
A thing's essence is its intrinsic nature [Aristotle]
     Full Idea: The what-it-was-to-be-that-thing [to ti en einai, essence] is, for each thing, what it is taken to be [kath' hauto, in virtue of itself] per se.
     From: Aristotle (Metaphysics [c.324 BCE], 1029b13)
     A reaction: [Translations is brackets from Vasilis Politis] Aristotle's other definition of essence is in terms of definition - Idea 10963 and Idea 11292.
An essence causes both its own unity and its kind [Aristotle]
     Full Idea: The what-it-was-to-be-that-thing [to ti en einai] is a unity of a kind straight off, just as it is a being of a kind. And that is why none of these things has some other cause of their being a unity, any more than they do of their being a being of a kind.
     From: Aristotle (Metaphysics [c.324 BCE], 1045b04)
     A reaction: This seems to be the key importance of the notion of essence - it is what both bestows unity on things in the world (which is basic to ontology and epistemology), and what enables us to categorise things (basic to epistemology).
Bodies need a soul (or something like it) to avoid being mere phenomena [Leibniz]
     Full Idea: Every substance is indivisible and consequently every corporeal substance must have a soul or at least an entelechy which is analogous to the soul, since otherwise bodies would be no more than phenomena.
     From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], G II 121), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 2
     A reaction: There is a large gap between having 'a soul' and having something 'analogous to a soul'. I take the analogy to be merely as originators of action. Leibniz wants to add appetite and sensation to the Aristotelian forms (but knows this is dubious!).
A substantial bond of powers is needed to unite composites, in addition to monads [Leibniz]
     Full Idea: Some realising thing must bring it about that composite substance contains something substantial besides monads, otherwise composites will be mere phenomena. The scholastics' active and passive powers are the substantial bond I am urging.
     From: Gottfried Leibniz (Letters to Des Bosses [1715], 1716.01.13), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 9
     A reaction: [compressed] This appears to be a major retreat, in the last year of Leibniz's life, from the full monadology he had espoused. How do monads connect to matter, and thus unify it? He is returning to Aristotelian hylomorphism.
Having an essence is the criterion of being a substance [Aristotle, by Lawson-Tancred]
     Full Idea: For Aristotle, having an essence is the criterion of being a substance.
     From: report of Aristotle (Metaphysics [c.324 BCE], 1030a) by Hugh Lawson-Tancred - Introductions to 'Metaphysics' p.178
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
The essence is the necessary properties, and the concept includes what is contingent [Leibniz]
     Full Idea: Of the essence of a particular thing is what pertains to it necessarily and perpetually; of the concept of an individual thing on the other hand is what pertains to it contingently or per accidens.
     From: Gottfried Leibniz (Human Freedom and Divine choice [1690], Grua 383), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 3.3.1
     A reaction: This arbitrates on the apparent conflict between his remarks in Idea 13077 and Idea 10382. There seems to be a distinction between the 'concept' of a thing, and the 'complete concept', the latter including the contingent properties.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
An 'idion' belongs uniquely to a thing, but is not part of its essence [Aristotle]
     Full Idea: A property [idion] is something which does not show the essence of a thing but belongs to it alone. ...No one calls anything a property which can possibly belong to something else.
     From: Aristotle (Topics [c.331 BCE], 102a18)
     A reaction: [See Charlotte Witt 106 on this] 'Property' is clearly a bad translation for such an individual item. Witt uses 'proprium', which is a necessary but nonessential property of something. Necessity is NOT the hallmark of essence. See Idea 12266.
The complete concept of an individual includes contingent properties, as well as necessary ones [Leibniz]
     Full Idea: In this complete concept of possible Peter are contained not only essential or necessary things, ..but also existential things, or contingent items included there, because the nature of an individual substance is to have a perfect or complete concept.
     From: Gottfried Leibniz (Of liberty, Fate and God's grace [1690], Grua 311), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 3.3.1
     A reaction: Compare Idea 13077, where he seems to say that the complete concept is only necessarily linked to properties which will predict future events - though I suppose that would have to include all of the contingent properties mentioned here.
A necessary feature (such as air for humans) is not therefore part of the essence [Leibniz]
     Full Idea: That which is necessary for something does not constitute its essence. Air is necessary for our life, but our life is something other than air.
     From: Gottfried Leibniz (Letters to Queen Charlotte [1702], 1702)
     A reaction: Bravo. Why can't modern philosophers hang on to this distinction? They seem to think that because they don't believe in traditional essences they can purloin the word for something else. Same with the word 'abstraction'.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / c. Essentials are necessary
The predicates of a thing's nature are necessary to it [Aristotle]
     Full Idea: Whatever is predicated in what something is is necessary.
     From: Aristotle (Posterior Analytics [c.327 BCE], 96b03)
     A reaction: This does NOT say that the essence is just the necessities. He goes on to say to say separately that certain properties of a triplet are part of the essence, as well as being necessary. This shows the nature of a thing is also necessary.
Aristotle doesn't see essential truths or essential properties as necessary [Aristotle, by Koslicki]
     Full Idea: Aristotle did not subscribe to the modal conception of essence. The essential truths are not even included among the necessary truths; and the essential features of an object are similarly not included among its necessary features.
     From: report of Aristotle (Metaphysics [c.324 BCE]) by Kathrin Koslicki - Essence, Necessity and Explanation 13.1
     A reaction: I take this point to be hugely important. There is no real role for essences in metaphysics if they are not of the Aristotelian type. The necessities just lead you to trivialities, or to conventions. Aristotelian essences lead you to facts.
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
The four explanations are the main aspects of a thing's nature [Aristotle, by Moravcsik]
     Full Idea: Aristotle sees as the main types of aitia (explanation) those that are also to be construed as the main aspects of the physis (nature) of anything.
     From: report of Aristotle (Physics [c.337 BCE]) by Julius Moravcsik - Aristotle on Adequate Explanations 1
     A reaction: Interestingly, this suggests that having rejected the Four Causes in favour of the Four Explanations, we might even consider them as the Four Natures, which ties explanation very closely to essence.
A thing's nature is what causes its changes and stability [Aristotle]
     Full Idea: The nature of a thing is a certain principle and cause of change and stability in the thing.
     From: Aristotle (Physics [c.337 BCE], 192b20)
     A reaction: A helpful contribution to the discussion, as most thinkers just boggle when asked to specify the core of something's identity. Aristotle's proposal links identity to causation, which is very appealing to a physical account of all of reality. Cf 5086.
Primary substances are ontological in 'Categories', and explanatory in 'Metaphysics' [Aristotle, by Wedin]
     Full Idea: The primacy of 'Categories' primary substances is a kind of ontological primacy, whereas the primacy of form is a kind of structural or explanatory primacy.
     From: report of Aristotle (Categories [c.331 BCE]) by Michael V. Wedin - Aristotle's Theory of Substance X.9
     A reaction: 'Structural' and 'explanatory' sound very different, since the former sounds ontological and the latter epistemological (and more subjective).
Aristotelian essences are properties mentioned at the starting point of a science [Aristotle, by Kung]
     Full Idea: As Aristotle uses the term 'essence', only those properties which are mentioned in or relatively close to the starting points of the science will be essential.
     From: report of Aristotle (Posterior Analytics [c.327 BCE]) by Joan Kung - Aristotle on Essence and Explanation II
     A reaction: I take this to be the correct way to understand Aristotelian essence - as something understood by its role in scientific explanations. We may, of course, work back to the starting point of a science, by disentangling the mess in the middle.
Metaphysics is the science of ultimate explanation, or of pure existence, or of primary existence [Aristotle, by Politis]
     Full Idea: In 'Metaphysics' Aristotle characterises metaphysics in three ways: as the science of the first or ultimate explanation of things; as the science of being qua being; and the science of primary being ('ousia').
     From: report of Aristotle (Metaphysics [c.324 BCE], book) by Vassilis Politis - Aristotle and the Metaphysics 2.1
     A reaction: I am a bit baffled about how anything worthwhile can be said about 'being qua being', but the other two seem worth pursuing, and may boil down to the same thing.
If you fully understand a subject and its qualities, you see how the second derive from the first [Leibniz]
     Full Idea: Every time we find some quality in a subject, we ought to think that, if we understood the nature of this subject and of this quality, we should conceive how this quality could result from it.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], Pref)
     A reaction: Thus (in Kripke's analogy) God cannot make 'subjects' on Thursday and then add 'qualities' on Friday. Add the point that all subjects are physical, and I say you have the whole story. The physical entails the mental. The laws result from the qualities.
9. Objects / D. Essence of Objects / 9. Essence and Properties
It is absurd that a this and a substance should be composed of a quality [Aristotle]
     Full Idea: Is it not impossible, even outrageous, that a this and a substance (even if it can be composed of constituents) should be composed not of substances and the this-thing-here but of a quality?
     From: Aristotle (Metaphysics [c.324 BCE], 1038b25)
     A reaction: This is to show Aristotle's deep hostility to anyone who thinks an essence is just a set of special properties (and the 'anyone' means just about anyone these days).
The properties of a thing flow from its essence [Leibniz]
     Full Idea: It is the same to look for perfection in an essence and in the properties that flow from an essence.
     From: Gottfried Leibniz (Letters to Wolff [1715], 1715.05.18)
     A reaction: It is helpful to have Leibniz spelling out his commitment to the traditional view of essence, as that from which the more evident properties flow.
Leibniz's view (that all properties are essential) is extreme essentialism, not its denial [Leibniz, by Mackie,P]
     Full Idea: The view standardly attributed to Leibniz, that makes all an individual's properties essential to it should be regarded as an extreme version of essentialism, not a denial of essentialism.
     From: report of Gottfried Leibniz (works [1690]) by Penelope Mackie - How Things Might Have Been 1.1
     A reaction: Wiggins disagrees, saying that Leibniz was not an essentialist, which is an interesting topic of research for those who are interested. I would take Leibniz to be not an essentialist, on that basis, as essentialism makes a distinction. See Quine on that.
9. Objects / D. Essence of Objects / 10. Essence as Species
Generic terms like 'man' are not substances, but qualities, relations, modes or some such thing [Aristotle]
     Full Idea: 'Man', and every generic term, denotes not an individual substance but a quality or relation or mode or something of the kind.
     From: Aristotle (Sophistical Refutations [c.331 BCE], 179a01)
     A reaction: This is Aristotle's denial that species constitutes the essence of anything. I take 'man' to be a categorisation of individuals, and is ontologically nothing at all in its own right.
Generalities like man and horse are not substances, but universal composites of account and matter [Aristotle]
     Full Idea: Man and horse and items similarly imposed on the particulars but themselves general are not substances but a kind of composite of the relevant account in the relevant matter, considered universally.
     From: Aristotle (Metaphysics [c.324 BCE], 1035b27)
     A reaction: Notice that these concepts are 'imposed' on particulars. This seems close to Locke's 'nominal' essence. It take this quotation to reinforce the priority of the particular in Aristotle's account.
Genera are not substances, and do not exist apart from the ingredient species [Aristotle]
     Full Idea: If 'man' and any other item similarly specified is a substance, then none of the contents of the account of man is a substance of anything. 'Animal', for instance, does not exist over and above particular animals.
     From: Aristotle (Metaphysics [c.324 BCE], 1038b31)
     A reaction: [I think 'particular animals' refers to species, not individuals, here] I take it as self-evident that this implies that species do not exist, apart from the individuals that constitute them.
'Categories' answers 'what?' with species, genus, differerentia; 'Met.' Z.17 seeks causal essence [Aristotle, by Wedin]
     Full Idea: Although what-is-it [ti esti] questions serve the classificatory project in 'Categories', they are no help in the causal enquiries of 'Metaphysics' Z.17. The essence of interest can't be the species or the differentia-cum-genus complex.
     From: report of Aristotle (Metaphysics [c.324 BCE], 1041a05-b36) by Michael V. Wedin - Aristotle's Theory of Substance X.4
     A reaction: Wedin's view is that these are compatible. The implication is that the nature of essence depends entirely on what it is you want to explain. Explain the category, or explain the behaviour?
Standardly, Aristotelian essences are taken to be universals of the species [Aristotle, by Witt]
     Full Idea: The standard interpretation holds that Aristotelian essences are species-essences, which are universal essences shared by all members of the same species.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Charlotte Witt - Substance and Essence in Aristotle Intro
     A reaction: Her aim is to refute this standard view, in defence of the view that Aristotle really wanted to pinpoint individual essences. I think Witt is correct.
In 'Met.' he says genera can't be substances or qualities, so aren't in the ontology [Aristotle, by Frede,M]
     Full Idea: In the central books of 'Metaphysics' there are no longer any genera or species. In Z.13 he argues that genera and universals can't be substances. Since genera are not qualities either, they disappear completely from the ontology.
     From: report of Aristotle (Metaphysics [c.324 BCE], Z.13) by Michael Frede - Title, Unity, Authenticity of the 'Categories' V
     A reaction: Music to my ears. It is so obvious to me that creatures are classified into genera, so genera can't exist separately, that I am bewildered anyone would believe or imply it.
Truths about species are eternal or necessary, but individual truths concern what exists [Leibniz]
     Full Idea: The concept of a species contains only eternal or necessary truths, whereas the concept of an individual contains, regarded as possible, what in fact exists or what is related to the existence of things and to time.
     From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.06)
     A reaction: This seems to be what is behind the preference some have for kind-essences rather than individual essences. But the individual must be explained, as well as the kind. Not all tigers are identical. The two are, of course, compatible.
For some sorts, a member of it is necessarily a member [Leibniz]
     Full Idea: There are sorts or species such that if an individual has ever been of such a sort or species it cannot (naturally, at least) stop being of it.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.06)
     A reaction: Note the thoughtful 'naturally, at least', which blocks genetic engineering. But natural selection is genetic engineering. Crucially, Leibniz is not attributing this to all sorts or species, and allows exceptions.
9. Objects / D. Essence of Objects / 11. Essence of Artefacts
Things are more unified if the unity comes from their own nature, not from external force [Aristotle]
     Full Idea: More unified is whatever is a whole with a certain shape and form, especially if it is by nature and not by force (e.g. by gluing or nailing or tying up), when, that is, it contains in itself the cause of its being continuous.
     From: Aristotle (Metaphysics [c.324 BCE], 1052a24)
     A reaction: [see also Phys 192b] This is about the only principle available for saying why the essence of an artefact is lesser than a natural essence. The healing of wounds shows that animals have a greater unity than tables?
The hallmark of an artefact is that its active source of maintenance is external [Aristotle, by Gill,ML]
     Full Idea: There is a critical line to be drawn between those entities whose active source of maintenance is internal and those whose source is external. This is the chief line that Aristotle draws between organisms and artefacts.
     From: report of Aristotle (Metaphysics [c.324 BCE], ess) by Mary Louise Gill - Aristotle on Substance Ch.7
     A reaction: Plants need water and sunlight, so I'm not sure that this marks the line quite clearly enough.
9. Objects / D. Essence of Objects / 12. Essential Parts
The same whole ceases to exist if a part is lost [Leibniz]
     Full Idea: We cannot say - with complete fidelity to the truth of things - that the same whole continues to exist if a part of it is lost.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 2.27.11)
     A reaction: This is the reference Simons 1987:319 gives when he claims that Leibniz accepts mereological essentialism. I think this is mereological necessity of identity, but not what I call 'essentialism'. That has to distinguish essential from non-essential.
A composite substance is a mere aggregate if its essence is just its parts [Leibniz]
     Full Idea: An aggregate, but not a composite substance, is resolved into parts. A composite substance only needs the coming together of parts, but is not essentially constituted by them, otherwise it would be an aggregate.
     From: Gottfried Leibniz (Letters to Des Bosses [1715], 1716.05.29)
     A reaction: The point is that there is more to some things than there mere parts. Only some unifying principle, in addition to the mere parts, bestows a unity. Mereology is a limited activity if it has nothing to say about this issue.
9. Objects / D. Essence of Objects / 13. Nominal Essence
We have a distinct idea of gold, to define it, but not a perfect idea, to understand it [Leibniz]
     Full Idea: That gold is a metal which resists cupellation and is insoluble in aquafortis is a distinct idea, for it gives us the criteria or definition of 'gold'. But it is not a perfect idea, because we know too little about cupellation and actions of aquafortis.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 2.31)
     A reaction: This connects the 'perfect idea' of something with knowing its active substance, and hence its essence. See Idea 12976 for the connection between perfect ideas and definitions.
If two people apply a single term to different resemblances, they refer to two different things [Leibniz]
     Full Idea: If one person applies the name 'avarice' to one resemblance, and some one else to another, there will be two different species designated by the same name.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 6.6.292), quoted by Nicholas Jolley - Leibniz and Locke on Essences p.199
     A reaction: Part of Leibniz's sustained attack on Locke's nominal essences. There is clearly an uninteresting nominal essence, where a 'big brown bear' is necessarily brown, but in the interesting respects I think Leibniz is right.
Locke needs many instances to show a natural kind, but why not a single instance? [Leibniz, by Jolley]
     Full Idea: Leibniz points out that it is a concealed premise of Locke's argument that if a natural kind exists it must have many instances, but there seems no a priori objection to the idea of a species with just one member.
     From: report of Gottfried Leibniz (New Essays on Human Understanding [1704], 6.6.311) by Nicholas Jolley - Leibniz and Locke on Essences p.200
     A reaction: I can't see this bothering Locke. Generally we formulate nominal essences by induction from bundles of ideas, but we can formulate a cautious first stab at it from one instance. If you see a new creature, is it a normal one, or a 'monster'?
9. Objects / D. Essence of Objects / 14. Knowledge of Essences
Aristotle claims that the individual is epistemologically prior to the universal [Aristotle, by Witt]
     Full Idea: Aristotle could have claimed that the universal is prior to the individual in the epistemic realm, but the individual is prior in the realm of being. ...Instead, he claims that the individual is epistemologically prior to the universal.
     From: report of Aristotle (Metaphysics [c.324 BCE], partic) by Charlotte Witt - Substance and Essence in Aristotle 5.1
     A reaction: This point strikes me as fairly self-evident. We only learn about the universal by induction from the individuals.
Actual knowledge is of the individual, and potential knowledge of the universal [Aristotle, by Witt]
     Full Idea: Aristotle resolves his aporia about substances and universals by distinguishing between actual knowledge, which is of the individual, and potential knowledge, which is of the universal.
     From: report of Aristotle (Metaphysics [c.324 BCE], potent) by Charlotte Witt - Substance and Essence in Aristotle
     A reaction: [See Witt 145-9 for the aporia] A vital piece in the jigsaw I am assembling. I connect this way of thinking with modern modal thinking, and actual and possible worlds. It obviously results in individual essences taking priority.
Essence is the distinct thinkability of anything [Leibniz]
     Full Idea: (Essence) is the distinct thinkability (cogitabilitas) of anything.
     From: Gottfried Leibniz (Notes on John Wilkins [1672], A6.2.487-8), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 1
     A reaction: A very original remark from the young Leibniz. It is neutral as to whether this is a real feature of objects, or a feature of human mental capacities. Presumably accidental features are thinkable, so 'distinct' is the key word.
9. Objects / D. Essence of Objects / 15. Against Essentialism
Leibniz was not an essentialist [Leibniz, by Wiggins]
     Full Idea: Leibniz was not an essentialist.
     From: report of Gottfried Leibniz (works [1690]) by David Wiggins - Sameness and Substance Renewed 4.2 n4
     A reaction: Assuming this is right, it is rather helpful, because you can read mountains of Leibniz without ever being quite sure. Mackie says he IS an extreme essentialist, treating all properties as essential. Wiggins makes more sense there.