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65 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
Essentialism says metaphysics can't be done by analysing unreliable language [Ellis]
     Full Idea: The new essentialism leads to a turning away from semantic analysis as a fundamental tool for the pursuit of metaphysical aims, ..since there is no reason to think that the language we speak accurately reflects the kind of world we live in.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: The last part of that strikes me as false. We have every reason to think that a lot of our language very accurately reflects reality. It had better, because we have no plan B. We should analyse our best concepts, but not outdated, culture-laden ones.
2. Reason / D. Definition / 3. Types of Definition
A decent modern definition should always imply a semantics [Hacking]
     Full Idea: Today we expect that anything worth calling a definition should imply a semantics.
     From: Ian Hacking (What is Logic? [1979], §10)
     A reaction: He compares this with Gentzen 1935, who was attempting purely syntactic definitions of the logical connectives.
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
     Full Idea: 'Dilution' (or 'Thinning') provides an essential contrast between deductive and inductive reasoning; for the introduction of new premises may spoil an inductive inference.
     From: Ian Hacking (What is Logic? [1979], §06.2)
     A reaction: That is, inductive logic (if there is such a thing) is clearly non-monotonic, whereas classical inductive logic is monotonic.
Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
     Full Idea: If A |- B and B |- C, then A |- C. This generalises to: If Γ|-A,Θ and Γ,A |- Θ, then Γ |- Θ. Gentzen called this 'cut'. It is the transitivity of a deduction.
     From: Ian Hacking (What is Logic? [1979], §06.3)
     A reaction: I read the generalisation as 'If A can be either a premise or a conclusion, you can bypass it'. The first version is just transitivity (which by-passes the middle step).
Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
     Full Idea: Only the cut rule can have a conclusion that is less complex than its premises. Hence when cut is not used, a derivation is quite literally constructive, building up from components. Any theorem obtained by cut can be obtained without it.
     From: Ian Hacking (What is Logic? [1979], §08)
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
The various logics are abstractions made from terms like 'if...then' in English [Hacking]
     Full Idea: I don't believe English is by nature classical or intuitionistic etc. These are abstractions made by logicians. Logicians attend to numerous different objects that might be served by 'If...then', like material conditional, strict or relevant implication.
     From: Ian Hacking (What is Logic? [1979], §15)
     A reaction: The idea that they are 'abstractions' is close to my heart. Abstractions from what? Surely 'if...then' has a standard character when employed in normal conversation?
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
     Full Idea: First-order logic is the strongest complete compact theory with a Löwenheim-Skolem theorem.
     From: Ian Hacking (What is Logic? [1979], §13)
A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
     Full Idea: Henkin proved that there is no first-order treatment of branching quantifiers, which do not seem to involve any idea that is fundamentally different from ordinary quantification.
     From: Ian Hacking (What is Logic? [1979], §13)
     A reaction: See Hacking for an example of branching quantifiers. Hacking is impressed by this as a real limitation of the first-order logic which he generally favours.
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order completeness seems to need intensional entities and possible worlds [Hacking]
     Full Idea: Second-order logic has no chance of a completeness theorem unless one ventures into intensional entities and possible worlds.
     From: Ian Hacking (What is Logic? [1979], §13)
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
     Full Idea: My doctrine is that the peculiarity of the logical constants resides precisely in that given a certain pure notion of truth and consequence, all the desirable semantic properties of the constants are determined by their syntactic properties.
     From: Ian Hacking (What is Logic? [1979], §09)
     A reaction: He opposes this to Peacocke 1976, who claims that the logical connectives are essentially semantic in character, concerned with the preservation of truth.
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
     Full Idea: For some purposes the variables of first-order logic can be regarded as prepositions and place-holders that could in principle be dispensed with, say by a system of arrows indicating what places fall in the scope of which quantifier.
     From: Ian Hacking (What is Logic? [1979], §11)
     A reaction: I tend to think of variables as either pronouns, or as definite descriptions, or as temporary names, but not as prepositions. Must address this new idea...
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
     Full Idea: A Löwenheim-Skolem theorem holds for anything which, on my delineation, is a logic.
     From: Ian Hacking (What is Logic? [1979], §13)
     A reaction: I take this to be an unusually conservative view. Shapiro is the chap who can give you an alternative view of these things, or Boolos.
8. Modes of Existence / B. Properties / 3. Types of Properties
Properties are 'dispositional', or 'categorical' (the latter as 'block' or 'intrinsic' structures) [Ellis, by PG]
     Full Idea: 'Dispositional' properties involve behaviour, and 'categorical properties' are structures in two or more dimensions. 'Block' structures (e.g. molecules) depend on other things, and 'instrinsic' structures (e.g. fields) involve no separate parts.
     From: report of Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.4) by PG - Db (ideas)
     A reaction: This is an essentialist approach to properties, and sounds correct to me. The crucial preliminary step to understanding properties is to eliminate secondary qualities (e.g. colour), which are not properties at all, and cause confusion.
8. Modes of Existence / B. Properties / 6. Categorical Properties
The passive view of nature says categorical properties are basic, but others say dispositions [Ellis]
     Full Idea: 'Categorical realism' is the most widely accepted theory of dispositional properties, because passivists can accept it, ..that is, that dispositions supervene on categorical properties; ..the opposite would imply nature is active and reactive.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.4)
     A reaction: Essentialists believe 'the opposite' - i.e. that dispositions are fundamental, and hence that the essence of nature is active. See 5468 for explanations of the distinctions. I am with the essentialists on this one.
8. Modes of Existence / B. Properties / 12. Denial of Properties
Redness is not a property as it is not mind-independent [Ellis]
     Full Idea: Redness is not a property, because it has no mind-independent existence.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3)
     A reaction: Well said. Secondary qualities are routinely cited in discussions of properties, and they shouldn't be. Redness causes nothing to happen in the physical world, unless a consciousness experiences it.
8. Modes of Existence / C. Powers and Dispositions / 5. Powers and Properties
Properties have powers; they aren't just ways for logicians to classify objects [Ellis]
     Full Idea: One cannot think of a property as just a set of objects in a domain (as Fregean logicians do), as though the property has no powers, but is just a way of classifying objects.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: I agree. It is sometimes suggested that properties are what 'individuate' objects, but how could they do that if they didn't have some power? If properties are known by their causal role, why do they have that causal role?
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
Nearly all fundamental properties of physics are dispositional [Ellis]
     Full Idea: With few, if any, exceptions, the fundamental properties of physical theory are dispositional properties of the things that have them.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3)
     A reaction: He is denying that they are passive (as Locke saw primary qualities), and says they are actively causal, or else capacities or propensities. Sounds right to me.
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
Indiscernibility is a necessary and sufficient condition for identity [Brody]
     Full Idea: Enduring objects should be taken as fundamental in an ontology, and for all such objects indiscernibility is both a necessary and sufficient condition for identity.
     From: Baruch Brody (Identity and Essence [1980], 3)
     A reaction: Brody offers a substantial defence, but I don't find it plausible. Apart from Black's well known twin spheres example (Idea 10195), discernibility is relative to the powers of the observer. Two similar people in the mist aren't thereby identical.
9. Objects / A. Existence of Objects / 5. Individuation / e. Individuation by kind
Brody bases sortal essentialism on properties required throughout something's existence [Brody, by Mackie,P]
     Full Idea: Brody bases sortal essentialism on the notion of a property that an individual must possess throughout its existence if it possesses it at any time in its existence.
     From: report of Baruch Brody (Identity and Essence [1980]) by Penelope Mackie - How Things Might Have Been 7.1
     A reaction: Brody tends to treat categories as properties, which I dislike. How do you assess 'must' here? A person may possess a mole throughout life without it being essential.
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
Modern emphasis is on properties had essentially; traditional emphasis is on sort-defining properties [Brody]
     Full Idea: The modern emphasis has been on the connection between essential properties and the properties that an object must have essentially. But traditionally there is also the connection between essential properties and the sort of thing that it is.
     From: Baruch Brody (Identity and Essence [1980], 5.6)
     A reaction: These are the modal essence and the definitional essence. My view is that he has missed out a crucial third (Aristotelian) view, which is that essences are explanatory. This third view can subsume the other two.
9. Objects / D. Essence of Objects / 1. Essences of Objects
Kripke and others have made essentialism once again respectable [Ellis]
     Full Idea: The revival of essentialism owes much to the work of Saul Kripke and Hilary Putnam, who made belief in essences once again respectable, with Harré and Madden arguing that there were real causal powers in nature.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Intro)
     A reaction: It seems to me important to separate two stages of this: 1) causation results from essences, and 2) essences can never change. The first seems persuasive to me. For the second, see METAPHYSICS/IDENTITY/COUNTERPARTS.
9. Objects / D. Essence of Objects / 2. Types of Essence
'Individual essences' fix a particular individual, and 'kind essences' fix the kind it belongs to [Ellis]
     Full Idea: The new essentialism retains Aristotelian ideas about essential properties, but it distinguishes more clearly between 'individual essences' and 'kind essences'; the former define a particular individual, the latter what kind it belongs to.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.1)
     A reaction: This might actually come into conflict with Aristotle, who seems to think that my personal essence is largely a human nature I share with everyone else. The new distinction is trying to keep the Kantian individual on the stage.
9. Objects / D. Essence of Objects / 5. Essence as Kind
A sortal essence is a property which once possessed always possessed [Brody, by Mackie,P]
     Full Idea: Brody bases sortal essentialism on the notion of a property that an individual must possess throughout its existence if it possesses it at any time in its existence. ...'Once an F, always an F'. ...Being a parrot is not a temporary occupation.
     From: report of Baruch Brody (Identity and Essence [1980]) by Penelope Mackie - How Things Might Have Been 7.1
     A reaction: Hm. Would being less than fifty metres tall qualify as a sortal essence, for a giraffe or a uranium rod? If there is one thing an essential property should be, it is important. How do we assess importance? By explanatory power! Watch this space.
Maybe essential properties are those which determine a natural kind? [Brody]
     Full Idea: We can advance the thesis that all essential properties either determine a natural kind or are part of an essential property that does determine a natural kind.
     From: Baruch Brody (Identity and Essence [1980])
     A reaction: A useful clear statement of the view. I am opposed to it, because I take it to be of the essence of Socrates that he is philosophical, but humans are not essentially philosophical, and philosophers are unlikely to be a natural kind.
9. Objects / D. Essence of Objects / 6. Essence as Unifier
De re essentialism standardly says all possible objects identical with a have a's essential properties [Brody]
     Full Idea: To say that an object a has a property P essentially is to say that it has P, and in all of certain worlds (all possible, all in which something identical with it exists, ...) the object identical with it has P. This is the standard de re interpretation.
     From: Baruch Brody (Identity and Essence [1980], 5.4)
     A reaction: This view always has to be qualified by excluding trivially necessary properties, but that exclusion shows clearly that the notion of essential is more concerned with non-triviality than it is with necessity.
9. Objects / D. Essence of Objects / 7. Essence and Necessity / a. Essence as necessary properties
Essentially, a has P, always had P, must have had P, and has never had a future without P [Brody]
     Full Idea: 'a has property P essentially' means 'a has P, a always had P, there is no possible past in which P exists without P, and there is no moment of time at which a has had P and at which there is a possible future in which a exists without P'
     From: Baruch Brody (Identity and Essence [1980], 6)
     A reaction: This is Brody's own final account of essentialism. This is a carefully qualified form of the view that essential properties are, on the whole, the necessary properties, which view I take to be fundamentally mistaken.
An object having a property essentially is equivalent to its having it necessarily [Brody]
     Full Idea: An object having a property essentially is equivalent to its having it necessarily.
     From: Baruch Brody (Identity and Essence [1980], 6.1)
     A reaction: This strikes me as blatantly false. Personally I am toying with the very unorthodox view that essential properties are not at all necessary, and that something can retain its identity while changing its essential character. A philosopher with Alzheimers.
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
Essentialism is justified if the essential properties of things explain their other properties [Brody]
     Full Idea: The reasonableness of the essentialist hypothesis will be proportional to the extent that we can, as a result, use a's possession of P to explain a's other properties, ...and there is an inability to explain otherwise why a has P.
     From: Baruch Brody (Identity and Essence [1980], 6.3)
     A reaction: Brody as a rather liberal notion of properties. I would hope that we can do rather more than explain a's non-essential properties. If the non-essential properties were entailed by the essential ones, would they not then also be essential?
9. Objects / D. Essence of Objects / 9. Essence and Properties
Essential properties are usually quantitatively determinate [Ellis]
     Full Idea: Most of the essential properties of things are quantitatively determinate properties.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3)
     A reaction: This makes the essential nature of the world very much the province of science, which deals in quantities and equations. Essentialists must deal with mental events, as well as basic physics.
9. Objects / D. Essence of Objects / 12. Essential Parts
Mereological essentialism says that every part that ensures the existence is essential [Brody]
     Full Idea: Mereological essentialism (whose leading advocate is Chisholm) says that for every x and y, if x is ever part of y, then y is necessarily such that x is part of y at any time that y exists.
     From: Baruch Brody (Identity and Essence [1980], 5.6)
     A reaction: This sounds implausible, especially given the transitivity of parthood. Not only are the planks that constitute Theseus's Ship now essential to it, but all the parts of the planks, every last chip, are as well.
9. Objects / D. Essence of Objects / 13. Nominal Essence
'Real essence' makes it what it is; 'nominal essence' makes us categorise it a certain way [Ellis]
     Full Idea: The 'real essence' of a thing is that set of its properties or structures in virtue of which it is a thing of that kind; its 'nominal essence' is the properties or structures in virtue of which it is described as a thing of that kind.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.1)
     A reaction: I like this distinction, because it is the kind made by realists like me who are fighting to make philosophers keep their epistemology and their ontology separate.
9. Objects / E. Objects over Time / 12. Origin as Essential
Interrupted objects have two first moments of existence, which could be two beginnings [Brody]
     Full Idea: If 'beginning of existence' meant 'first moment of existence after a period of nonexistence', then objects with interrupted existence have two beginnings of existence.
     From: Baruch Brody (Identity and Essence [1980], 4.1)
     A reaction: One might still maintain that the first beginning was essential to the object, since that is the event that defined it - and that would clarify the reason why we are supposed to think the origins are essential. I say the origin explains it.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
One thing can look like something else, without being the something else [Ellis]
     Full Idea: In considering questions of real possibility, it is important to keep the distinction between what a thing is and what it looks like clearly in mind. There is a possible world containing a horse that could then look like a cow, but it wouldn't BE a horse.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.6)
     A reaction: This is an interesting test assertion of the notion that there are essences (although Ellis does not allow that animals actually have essences - how could you, given evolution?). His point is a good one.
a and b share all properties; so they share being-identical-with-a; so a = b [Brody]
     Full Idea: Suppose that a and b have all of their properties in common. a certainly has the property of-being-identical-with-a. So, by supposition, does b. Then a = b.
     From: Baruch Brody (Identity and Essence [1980], 1.2)
     A reaction: Brody defends this argument, and seems to think that it proves the identity of indiscernibles. As far as I can see it totally begs the question, since we can only assume that both have the property of being-identical-with-a if we have assumed a = b.
10. Modality / B. Possibility / 1. Possibility
Scientific essentialists say science should define the limits of the possible [Ellis]
     Full Idea: Scientific essentialists hold that one of the primary aims of science is to define the limits of the possible.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.6)
     A reaction: I'm not sure working scientists will go along with that, but I like the claim that philosophy is very much part of the same enterprise as practical science (and NOT subservient to it!). I think of metaphysics as very high level physics.
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Essentialists deny possible worlds, and say possibilities are what is compatible with the actual world [Ellis]
     Full Idea: Essentialists are modal realists; ..what is really possible, they say, is what is compatible with the natures of things in this world (and this does not commit them to the existence of any world other than the actual world).
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: This introduces something like 'compatibilities' into our ontology. That must rest on some kind of idea of a 'natural contradiction'. We can discuss the possibilities resulting from essences, but what are the possible variations in the essences?
10. Modality / C. Sources of Modality / 6. Necessity from Essence
Metaphysical necessities are true in virtue of the essences of things [Ellis]
     Full Idea: Metaphysical necessities are propositions that are true in virtue of the essences of things.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.1)
     A reaction: I am cautious about this. It sounds like huge Leibnizian metaphysical claims riding in on the back of a rather sensible new view of the laws of science. How can we justify equating natural necessity with metaphysical necessity?
10. Modality / D. Knowledge of Modality / 3. A Posteriori Necessary
Essentialists say natural laws are in a new category: necessary a posteriori [Ellis]
     Full Idea: Essentialists do not accept the standard position, which says necessity is a priori, and contingency is a posteriori. They have a radically new category: the necessary a posteriori. The laws of nature are, for example, both necessary and a posteriori.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.6)
     A reaction: Based on Kripke. I'm cautious about this. Presumably God, who would know the essences, could therefore infer the laws a priori. The laws may follow of necessity from the essences, but the essences can't be known a posteriori to be necessary.
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
Imagination tests what is possible for all we know, not true possibility [Ellis]
     Full Idea: The imaginability test of possibility confuses what is really or metaphysically possible with what is only epistemically possible. ..The latter is just what is possible for all we know.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.6)
10. Modality / E. Possible worlds / 1. Possible Worlds / c. Possible worlds realism
Possible worlds realism is only needed to give truth conditions for modals and conditionals [Ellis]
     Full Idea: The main trouble with possible worlds realism is that the only reason anyone has, or ever could have, to believe in other possible worlds (other than this one) is that they are needed, apparently, to provide truth conditions for modals and conditionals.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: This attacks Lewis. Ellis makes this sound like a trivial technicality, but if our metaphysics is going to make sense it must cover modals and conditionals. What do they actually mean? Lewis has a theory, at least.
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
Identity across possible worlds is prior to rigid designation [Brody]
     Full Idea: Identity across possible worlds is prior to rigid designation.
     From: Baruch Brody (Identity and Essence [1980], 5.4)
     A reaction: An interesting view. We might stipulate that any possible Aristotle is 'our Aristotle', but you would still need criteria for deciding which possible Aristotle's would qualify. Long-frozen Aristotles, stupid Aristotles, alien Aristotle's, deformed...
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / b. Primary/secondary
Essentialists mostly accept the primary/secondary qualities distinction [Ellis]
     Full Idea: Essentialists mostly accept the distinction between primary and secondary qualities, ..where the primary qualities of things are those that are intrinsic to the objects that have them.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3)
     A reaction: One reason I favour essentialism is because I have always thought that the primary/secondary distinction was a key to understanding the world. 'Primary' gets at the ontology, 'secondary' shows us the epistemology.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / c. Primary qualities
Primary qualities are number, figure, size, texture, motion, configuration, impenetrability and (?) mass [Ellis]
     Full Idea: For Boyle, Locke and Newton, the qualities inherent in bodies were just the primary qualities, namely number, figure, size, texture, motion and configuration of parts, impenetrability and, perhaps, body (or mass).
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.4)
     A reaction: It is nice to have a list. Ellis goes on to say these are too passive, and urges dispositions as primary. Even so, the original seventeenth century insight seems to me a brilliant step forward in our understanding of the world.
14. Science / C. Induction / 5. Paradoxes of Induction / a. Grue problem
Emeralds are naturally green, and only an external force could turn them blue [Ellis]
     Full Idea: Emeralds cannot all turn blue in 2050 (as Nelson Goodman envisaged), because to do so they would have to have an extrinsically variable nature.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: I was never very impressed by the 'grue' problem, probably for this reason, but also because Goodman probably thought predicates and properties are the same thing, which they aren't (Idea 5457).
14. Science / D. Explanation / 2. Types of Explanation / f. Necessity in explanations
Essentialists don't infer from some to all, but from essences to necessary behaviour [Ellis]
     Full Idea: For essentialists the problem of induction reduces to discovering what natural kinds there are, and identifying their essential problems and structures. We then know how they must behave in any world, and there is no inference from some to all.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: The obvious question is how you would determine the essences if you are not allowed to infer 'from some to all'. Personally I don't see induction as a problem, because it is self-evidently rational in a stable world. Hume was right to recommend caution.
19. Language / C. Assigning Meanings / 3. Predicates
Predicates assert properties, values, denials, relations, conventions, existence and fabrications [Ellis, by PG]
     Full Idea: As well as properties, predicates can assert evaluation, denial, relations, conventions, existence or fabrication.
     From: report of Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3) by PG - Db (ideas)
     A reaction: This seems important, in order to disentangle our ontological commitments from our language, which was a confusion that ran throughout twentieth-century philosophy. A property is a real thing in the world, not a linguistic convention.
20. Action / B. Preliminaries of Action / 2. Willed Action / c. Agent causation
Regularity theories of causation cannot give an account of human agency [Ellis]
     Full Idea: A Humean theory of causation (as observed regularities) makes it very difficult for anyone even to suggest a plausible theory of human agency.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: I'm not quite sure what a 'theory' of human agency would look like. Hume himself said we only get to understand our mental powers from repeated experience (Idea 2220). How do we learn about the essence of our own will?
20. Action / C. Motives for Action / 1. Acting on Desires
Humans have variable dispositions, and also power to change their dispositions [Ellis]
     Full Idea: It seems that human beings not only have variable dispositional properties, as most complex systems have, but also meta-powers: powers to change their own dispositional properties.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: This seems to me a key to how we act, and also to morality. 'What dispositions do you want to have?' is the central question of virtue theory. Humans are essentially multi-level thinkers. Irony is the window into the soul.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Essentialism fits in with Darwinism, but not with extreme politics of left or right [Ellis]
     Full Idea: The extremes of left and right in politics have much more reason than Darwinists to be threatened by the 'new essentialism', because it must reinstate the concept of human nature.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: The point being that political extremes go against the grain of our nature. Personally I am favour of essentialism, and human nature. I notice that Steven Pinker is now defending human nature, from a background of linguistics and psychology.
26. Natural Theory / B. Natural Kinds / 1. Natural Kinds
Natural kinds are of objects/substances, or events/processes, or intrinsic natures [Ellis]
     Full Idea: Natural kinds appear to be of objects or substances, or of events or processes, or of the intrinsic nature of things; hence there should be laws of nature specific to each of these categories.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.5)
     A reaction: It is nice to see someone actually discussing what sort of natural kinds there are, instead of getting bogged down in how natural kinds terms get their meaning or reference. Ellis recognises that 'intrinsic nature' needs some discussion.
26. Natural Theory / B. Natural Kinds / 4. Source of Kinds
Essentialism says natural kinds are fundamental to nature, and determine the laws [Ellis]
     Full Idea: According to essentialists, the world is wholly structured at the most fundamental level into natural kinds, and the laws of nature are all determined by those kinds.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.5)
     A reaction: I am a fan of this view, despite being cautious about claims that natural kinds have necessary identity. Why are the essences active? That is the old Greek puzzle about the origin of movement. And why are natural kinds stable?
26. Natural Theory / B. Natural Kinds / 6. Necessity of Kinds
For essentialists two members of a natural kind must be identical [Ellis]
     Full Idea: Modern essentialists would insist that any two members of the same natural kind must be identical in all essential respects.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.1)
     A reaction: For this reason, animals no longer qualify as natural kinds, but electrons, gold atoms, and water molecules do. My sticking point is when anyone asserts that an electron necessarily has (say) its mass. Why no close counterpart of electrons?
The whole of our world is a natural kind, so all worlds like it necessarily have the same laws [Ellis]
     Full Idea: It is plausible to suppose that the world is an instance of a natural kind, ..and what is naturally necessary in our world is what must be true in any world of the same natural kind.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.6)
     A reaction: This is putting an awful lot of metaphysical weight on the concept of a 'natural kind', so it had better be a secure one. If we accept that natural laws necessarily follow from essences, why shouldn't the whole of our world have an essence, as water does?
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
Essentialists regard inanimate objects as genuine causal agents [Ellis]
     Full Idea: Essentialist suppose that the inanimate objects of nature are genuine causal agents: things capable of acting or interacting.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Intro)
     A reaction: I have no idea how one might demonstrate such a fact, even though it seems to stare us in the face. This is where science bumps into philosophy. I find myself intuitively taking the essentialist side quite strongly.
Essentialists believe causation is necessary, resulting from dispositions and circumstances [Ellis]
     Full Idea: Essentialists believe elementary causal relations involve necessary connections between events, namely between the displays of dispositional properties and the circumstances that give rise to them.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.4)
     A reaction: I like essentialism, but I feel a Humean caution about talk of 'natural necessity'. Let's just say that causation seems to be entirely the result of the nature of how things are. How things could be is a large topic for little mites like us.
A general theory of causation is only possible in an area if natural kinds are involved [Ellis]
     Full Idea: A general theory of causation in an area is possible only if the kinds of entities under investigation can reasonably be assumed to belong to natural kinds.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: Human beings will be a problem, and also different levels of natural kinds (e.g. a chemical and an organism). 'Natural kind' is a very loose concept. He is referring to scientific, rather than philosophical, theories, I presume.
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
For 'passivists' behaviour is imposed on things from outside [Ellis]
     Full Idea: A 'passivist' believes that the tendencies of things to behave as they do can never be inherent in the things themselves; they must always be imposed on them from the outside.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Intro)
     A reaction: This is the medieval view, inherited by Newton and Hume, which makes miracles a possibility, and makes the laws of nature contingent. Essentialism disagree. I think I am with the essentialists.
The laws of nature imitate the hierarchy of natural kinds [Ellis]
     Full Idea: If the natural kinds are divided into hierarchical categories, then essentialists would expect the laws of nature also to divide up into these categories, with the same hierarchy.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.5)
     A reaction: This seems to me a real step forwards in our understanding of nature, and hence a nice example of the contribution which philosophy can make, instead of just physics.
Laws of nature tend to describe ideal things, or ideal circumstances [Ellis]
     Full Idea: Most of the propositions we think of as being (or as expressing) genuine laws of nature seem to describe only the behaviour of ideal kinds of things, or of things in ideal circumstances.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.5)
     A reaction: Ellis this suggests that this phenomenon is because science aims at broad understanding instead of strict prediction. Do we simplify because we are a bit dim? Or is it because generalisation wouldn't exist without idealisation and abstraction?
We must explain the necessity, idealisation, ontology and structure of natural laws [Ellis]
     Full Idea: There are four major problems about the laws of nature: a necessity problem (must they be true?), an idealisation problem (why is this preferable?), an ontological problem (their grounds), and a structural problem (their relationships).
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.5)
     A reaction: One might also ask why the laws (or their underlying essences) are the way they are, and not some other way, though the prospects of answering that don't look good. I don't think we should be satisfied with saying all of these questions are hopeless.
26. Natural Theory / D. Laws of Nature / 4. Regularities / a. Regularity theory
Causal relations cannot be reduced to regularities, as they could occur just once [Ellis]
     Full Idea: Causal relations cannot be reduced to mere regularities, as Hume supposed, as they could exist as a singular case, even if it never happened on more than one occasions.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3)
     A reaction: This seems to be the key reason for modern views moving away from Hume. The suspicion is that regularity is a test for or symptom of causation, but we are deeply committed to the real nature of causation being whatever creates the regularities.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
Essentialists say dispositions are basic, rather than supervenient on matter and natural laws [Ellis]
     Full Idea: Essentialists say that dispositional properties may be fundamental, whereas for a passivist such qualities are not primary, but supervene on the primary qualities of matter, and on the laws of nature.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3)
     A reaction: I am strongly in favour of this view of nature. Without essentialism, we have laws of nature arising out of a total void (or God), and arbitrarily imposing themselves on matter. What are the 'primary qualities of matter', if not dispositions?
The essence of uranium is its atomic number and its electron shell [Ellis]
     Full Idea: The essential properties of uranium are its atomic number, and the common electron shell structure for all uranium atoms.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.3)
     A reaction: For those who deny essences (e.g. Quineans) this is a nice challenge. You might have to add accounts of the essences of the various particles that make up the atoms. There is nothing arbitrary or conventional about what makes something uranium.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / b. Scientific necessity
For essentialists, laws of nature are metaphysically necessary, being based on essences of natural kinds [Ellis]
     Full Idea: Essentialist believe the laws of nature are metaphysically necessary, because anything that belongs to a natural kind is logically required (or is necessarily disposed) to behave as its essential properties dictate.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.4)
     A reaction: What a thrillingly large claim. Best approached with caution.. If we say 'essences make laws, and essences are necessary', we might wonder whether a natural kind essence could be SLIGHTLY different (a counterpart) in another world.
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / d. Knowing essences
Essentialism requires a clear separation of semantics, epistemology and ontology [Ellis]
     Full Idea: Scientific essentialism requires that philosophers distinguish clearly between semantic issues, epistemological issues, and ontological issues.
     From: Brian Ellis (The Philosophy of Nature: new essentialism [2002], Ch.7)
     A reaction: Music to my ears - but then I think everyone should require that of philosophers, because it where they get themselves most confused. The trouble is that ontology is only obtainable epistemologically, and only expressible semantically.