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All the ideas for 'Logical Pluralism', 'Why Propositions Aren't Truth-Supporting Circumstance' and 'The Problem of the Soul'

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48 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Philosophy needs wisdom about who we are, as well as how we ought to be [Flanagan]
     Full Idea: Any good philosophy will need to offer wisdom about who we are as well as about how we ought to be.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 14)
     A reaction: This sop should be accepted gratefully by fans of bioethics, who seem inclined to think that describing 'how we are' is all that needs to be said. Maybe the key wisdom lies in the relationship between the 'is' and the 'ought' of human nature.
1. Philosophy / G. Scientific Philosophy / 1. Aims of Science
We resist science partly because it can't provide ethical wisdom [Flanagan]
     Full Idea: The inability of science to provide ethical wisdom is partly responsible for our resistance to the scientific image.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 14)
     A reaction: This seems right. A.J. Ayer, for example, declared "I believe in science", and his account of ethics was vacuously nihilistic. A description of the mechanisms of moral life is not the same as ethical wisdom.
3. Truth / A. Truth Problems / 1. Truth
Some truths have true negations [Beall/Restall]
     Full Idea: Dialetheism is the view that some truths have true negations.
     From: JC Beall / G Restall (Logical Pluralism [2006], 7.4)
     A reaction: The important thing to remember is that they are truths. Thus 'Are you feeling happy?' might be answered 'Yes and no'.
3. Truth / B. Truthmakers / 5. What Makes Truths / b. Objects make truths
A truthmaker is an object which entails a sentence [Beall/Restall]
     Full Idea: The truthmaker thesis is that an object is a truthmaker for a sentence if and only if its existence entails the sentence.
     From: JC Beall / G Restall (Logical Pluralism [2006], 5.5.3)
     A reaction: The use of the word 'object' here is even odder than usual, and invites many questions. And the 'only if' seems peculiar, since all sorts of things can make a sentence true. 'There is someone in the house' for example.
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
(∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically [Beall/Restall]
     Full Idea: The inference of 'distribution' (∀x)(A v B) |- (∀x)A v (∃x)B) is valid in classical logic but invalid intuitionistically. It is straightforward to construct a 'stage' at which the LHS is true but the RHS is not.
     From: JC Beall / G Restall (Logical Pluralism [2006], 6.1.2)
     A reaction: This seems to parallel the iterative notion in set theory, that you must construct your hierarchy. All part of the general 'constructivist' approach to things. Is some kind of mad platonism the only alternative?
4. Formal Logic / E. Nonclassical Logics / 5. Relevant Logic
Excluded middle must be true for some situation, not for all situations [Beall/Restall]
     Full Idea: Relevant logic endorses excluded middle, ..but says instances of the law may fail. Bv¬B is true in every situation that settles the matter of B. It is necessary that there is some such situation.
     From: JC Beall / G Restall (Logical Pluralism [2006], 5.2)
     A reaction: See next idea for the unusual view of necessity on which this rests. It seems easier to assert something about all situations than just about 'some' situation.
It's 'relevantly' valid if all those situations make it true [Beall/Restall]
     Full Idea: The argument from P to A is 'relevantly' valid if and only if, for every situation in which each premise in P is true, so is A.
     From: JC Beall / G Restall (Logical Pluralism [2006], 5.2)
     A reaction: I like the idea that proper inference should have an element of relevance to it. A falsehood may allow all sorts of things, without actually implying them. 'Situations' sound promising here.
Relevant consequence says invalidity is the conclusion not being 'in' the premises [Beall/Restall]
     Full Idea: Relevant consequence says the conclusion of a relevantly invalid argument is not 'carried in' the premises - it does not follow from the premises.
     From: JC Beall / G Restall (Logical Pluralism [2006], 5.3.3)
     A reaction: I find this appealing. It need not invalidate classical logic. It is just a tougher criterion which is introduced when you want to do 'proper' reasoning, instead of just playing games with formal systems.
Relevant logic does not abandon classical logic [Beall/Restall]
     Full Idea: We have not abandoned classical logic in our acceptance of relevant logic.
     From: JC Beall / G Restall (Logical Pluralism [2006], 5.4)
     A reaction: It appears that classical logic is straightforwardly accepted, but there is a difference of opinion over when it is applicable.
A doesn't imply A - that would be circular [Beall/Restall]
     Full Idea: We could reject the inference from A to itself (on grounds of circularity).
     From: JC Beall / G Restall (Logical Pluralism [2006], 8)
     A reaction: [Martin-Meyer System] 'It's raining today'. 'Are you implying that it is raining today?' 'No, I'm SAYING it's raining today'. Logicians don't seem to understand the word 'implication'. Logic should capture how we reason. Nice proposal.
Relevant logic may reject transitivity [Beall/Restall]
     Full Idea: Some relevant logics reject transitivity, but we defend the classical view.
     From: JC Beall / G Restall (Logical Pluralism [2006], 8)
     A reaction: [they cite Neil Tennant for this view] To reject transitivity (A?B ? B?C ? A?C) certainly seems a long way from classical logic. But in everyday inference Tennant's idea seems good. The first premise may be irrelevant to the final conclusion.
4. Formal Logic / E. Nonclassical Logics / 6. Free Logic
Free logic terms aren't existential; classical is non-empty, with referring names [Beall/Restall]
     Full Idea: A logic is 'free' to the degree it refrains from existential import of its singular and general terms. Classical logic must have non-empty domain, and each name must denote in the domain.
     From: JC Beall / G Restall (Logical Pluralism [2006], 7.1)
     A reaction: My intuition is that logic should have no ontology at all, so I like the sound of 'free' logic. We can't say 'Pegasus does not exist', and then reason about Pegasus just like any other horse.
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic studies consequence; logical truths are consequences of everything, or nothing [Beall/Restall]
     Full Idea: Nowadays we think of the consequence relation itself as the primary subject of logic, and view logical truths as degenerate instances of this relation. Logical truths follow from any set of assumptions, or from no assumptions at all.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.2)
     A reaction: This seems exactly right; the alternative is the study of necessities, but that may not involve logic.
Syllogisms are only logic when they use variables, and not concrete terms [Beall/Restall]
     Full Idea: According to the Peripatetics (Aristotelians), only syllogistic laws stated in variables belong to logic, and not their applications to concrete terms.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.5)
     A reaction: [from Lukasiewicz] Seems wrong. I take it there are logical relations between concrete things, and the variables are merely used to describe these relations. Variables lack the internal powers to drive logical necessities. Variables lack essence!
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
The view of logic as knowing a body of truths looks out-of-date [Beall/Restall]
     Full Idea: Through much of the 20th century the conception of logic was inherited from Frege and Russell, as knowledge of a body of logical truths, as arithmetic or geometry was a knowledge of truths. This is odd, and a historical anomaly.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.2)
     A reaction: Interesting. I have always taken this idea to be false. I presume logic has minimal subject matter and truths, and preferably none at all.
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Logic studies arguments, not formal languages; this involves interpretations [Beall/Restall]
     Full Idea: Logic does not study formal languages for their own sake, which is formal grammar. Logic evaluates arguments, and primarily considers formal languages as interpreted.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.1)
     A reaction: Hodges seems to think logic just studies formal languages. The current idea strikes me as a much more sensible view.
5. Theory of Logic / A. Overview of Logic / 8. Logic of Mathematics
The model theory of classical predicate logic is mathematics [Beall/Restall]
     Full Idea: The model theory of classical predicate logic is mathematics if anything is.
     From: JC Beall / G Restall (Logical Pluralism [2006], 4.2.1)
     A reaction: This is an interesting contrast to the claim of logicism, that mathematics reduces to logic. This idea explains why students of logic are surprised to find themselves involved in mathematics.
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
There are several different consequence relations [Beall/Restall]
     Full Idea: We are pluralists about logical consequence because we take there to be a number of different consequence relations, each reflecting different precisifications of the pre-theoretic notion of deductive logical consequence.
     From: JC Beall / G Restall (Logical Pluralism [2006], 8)
     A reaction: I don't see how you avoid the slippery slope that leads to daft logical rules like Prior's 'tonk' (from which you can infer anything you like). I say that nature imposes logical conquence on us - but don't ask me to prove it.
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
A sentence follows from others if they always model it [Beall/Restall]
     Full Idea: The sentence X follows logically from the sentences of the class K if and only if every model of the class K is also a model of the sentence X.
     From: JC Beall / G Restall (Logical Pluralism [2006], 3.2)
     A reaction: This why the symbol |= is often referred to as 'models'.
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logical truth is much more important if mathematics rests on it, as logicism claims [Beall/Restall]
     Full Idea: If mathematical truth reduces to logical truth then it is important what counts as logically true, …but if logicism is not a going concern, then the body of purely logical truths will be less interesting.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.2)
     A reaction: Logicism would only be one motivation for pursuing logical truths. Maybe my new 'Necessitism' will derive the Peano Axioms from broad necessary truths, rather than from logic.
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / d. The Preface paradox
Preface Paradox affirms and denies the conjunction of propositions in the book [Beall/Restall]
     Full Idea: The Paradox of the Preface is an apology, that you are committed to each proposition in the book, but admit that collectively they probably contain a mistake. There is a contradiction, of affirming and denying the conjunction of propositions.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.4)
     A reaction: This seems similar to the Lottery Paradox - its inverse perhaps. Affirm all and then deny one, or deny all and then affirm one?
10. Modality / A. Necessity / 3. Types of Necessity
Relevant necessity is always true for some situation (not all situations) [Beall/Restall]
     Full Idea: In relevant logic, the necessary truths are not those which are true in every situation; rather, they are those for which it is necessary that there is a situation making them true.
     From: JC Beall / G Restall (Logical Pluralism [2006], 5.2)
     A reaction: This seems to rest on the truthmaker view of such things, which I find quite attractive (despite Merricks's assault). Always ask what is making some truth necessary. This leads you to essences.
14. Science / A. Basis of Science / 4. Prediction
Explanation does not entail prediction [Flanagan]
     Full Idea: Explanation does not entail prediction.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 73n)
     A reaction: Presumably the inverse of this is also true, as we might be able to predict through pure induction, without knowing why something happened. We predict that smoking is likely to cause cancer. Complex things might be explicable but unpredictable.
15. Nature of Minds / A. Nature of Mind / 3. Mental Causation
In the 17th century a collisionlike view of causation made mental causation implausible [Flanagan]
     Full Idea: In the seventeenth century the dominant idea that causation is collisionlike made mental causation almost impossible to envision.
     From: Owen Flanagan (The Problem of the Soul [2002], p.136)
     A reaction: Interesting. This makes Descartes' interaction theory look rather bold, and Leibniz's and Malebranche's rejection of it understandable. Personally I still think of causation as collisionlike, except that the collisions are of very very tiny objects.
15. Nature of Minds / B. Features of Minds / 3. Privacy
Only you can have your subjective experiences because only you are hooked up to your nervous system [Flanagan]
     Full Idea: It is easy to explain why certain brain events are uniquely experienced by you subjectively: only you are properly hooked up to your own nervous system to have your own experiences.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 87)
     A reaction: This is in reply to Nagel's oft quoted claim that mind can only be understood as "what it is like to be" that mind. I agree with Flanagan, and it is nice illustration of how philosophers can confuse themselves with high-sounding questions.
16. Persons / D. Continuity of the Self / 2. Mental Continuity / b. Self as mental continuity
We only have a sense of our self as continuous, not as exactly the same [Flanagan]
     Full Idea: We only have a sense of our self as continuous, but not as exactly the same.
     From: Owen Flanagan (The Problem of the Soul [2002], p.178)
     A reaction: Russell said this too, and it seems to me to be right. Personal identity is far too imprecise for me to assert that I remember my ten-year-old self as being identical to me now. Only physical objects like teddy bears can pass that test.
16. Persons / E. Rejecting the Self / 3. Narrative Self
The self is an abstraction which magnifies important aspects of autobiography [Flanagan]
     Full Idea: The self is an abstraction from the story of a person's life that isolates and magnifies the experiences, traits and aspirations that are assigned importance.
     From: Owen Flanagan (The Problem of the Soul [2002], p.240)
     A reaction: Personally I am inclined to see personal identity as the central controller of brain activity, the aspect of the biological machine which keeps all the mental events focused on what matters, which is health, safety and happiness.
We are not born with a self; we develop a self through living [Flanagan]
     Full Idea: It is a bad mistake to think we are born with a self; the self develops, and acquiring it requires living in the world.
     From: Owen Flanagan (The Problem of the Soul [2002], p.260)
     A reaction: I think this is wrong. He is mistaking a complex cultural concept of the self as the subject for autobiography etc. for the basic biological self which even small animals must have if their brains are to serve any useful purpose in their lives.
16. Persons / E. Rejecting the Self / 4. Denial of the Self
For Buddhists a fixed self is a morally dangerous illusion [Flanagan]
     Full Idea: According to Buddhism, the idea of a permanent, constant self is an illusion, and a morally dangerous one.
     From: Owen Flanagan (The Problem of the Soul [2002], p.161)
     A reaction: We are familiar with the idea that it might be an illusion, but I am unconvinced by 'morally dangerous'. If you drop both free will and personal identity, I can't see any sort of focus for moral life left, but I am willing to be convinced.
16. Persons / F. Free Will / 1. Nature of Free Will
Normal free will claims control of what I do, but a stronger view claims control of thought and feeling [Flanagan]
     Full Idea: The standard view of free will is that I have something like complete control over what I do. A stronger view (not widely held) is that I also have complete control over what I think and what I feel.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 60n)
     A reaction: To claim free control of feelings looks optimistic, but it does look as if we can decide to think about something, such as a philosophical problem. Deciding what to say comes somewhere between thought and action.
Free will is held to give us a whole list of desirable capacities for living [Flanagan]
     Full Idea: Free will is said to give us self-control, self-expression, individuality, reasons-sensitivity, rational deliberation, rational accountability, moral accountability, the capacity to do otherwise, unpredictability, and political freedom.
     From: Owen Flanagan (The Problem of the Soul [2002], p.104)
     A reaction: Nice list. His obvious challenge is to either say we can live happily without some of these things, or else show how we can have them without 'free will'. Personally I agree with Flanagan that we meet the challenge.
16. Persons / F. Free Will / 5. Against Free Will
People believe they have free will that circumvents natural law, but only an incorporeal mind could do this [Flanagan]
     Full Idea: Most people believe we have free will, and that this consists in the ability to circumvent natural law. The trouble is that the only device ever philosophically invented that can do this sort of job is an incorporeal soul or mind.
     From: Owen Flanagan (The Problem of the Soul [2002], Pref)
     A reaction: I think this is exactly right. We currently have a western world full of people who have rejected dualism, but still cling on to free will, because they think morality depends on it. I think morality depends on personal identity, but not on free will.
We only think of ourselves as having free will because we first thought of God that way [Flanagan]
     Full Idea: It is unimaginable to me that, despite the feeling that we control what we do, such a strong conception of ourselves as unmoved movers would have been added to our self-image unless we had first conceived of God along these lines.
     From: Owen Flanagan (The Problem of the Soul [2002], p.107)
     A reaction: I think this is right, though there are signs in fifth century Greece of contradictory evidence. The 'unmoved mover' seems unformulated before Plato's 'Laws' (idea 1423), but there is an implied belief in free will a hundred years earlier.
17. Mind and Body / A. Mind-Body Dualism / 8. Dualism of Mind Critique
People largely came to believe in dualism because it made human agents free [Flanagan]
     Full Idea: I would say that that my consciousness doesn't seem either physical or non-physical, ..but the belief that the mind is non-physical partly took hold because that fits well with thinking of human agents as free.
     From: Owen Flanagan (The Problem of the Soul [2002], p.102)
     A reaction: I think this is right. I personally think there is no such thing as free will, and that belief in it has been the single greatest delusion amongst philosophers (and others) for the last two thousand years. Dualism has now gone, and free will is next.
17. Mind and Body / B. Behaviourism / 4. Behaviourism Critique
Behaviourism notoriously has nothing to say about mental causation [Flanagan]
     Full Idea: Behaviourism was notorious in its heyday for having nothing to say about mental causation.
     From: Owen Flanagan (The Problem of the Soul [2002], p.141)
     A reaction: This is a bit unfair, as Ryle (idea 2622, following Spinoza, 4862) was one of the first to point out the paradox of 'double causation'. You have to be a mentalist to worry about mental causation, and eliminativists aren't bothered.
17. Mind and Body / D. Property Dualism / 2. Anomalous Monism
Cars and bodies obey principles of causation, without us knowing any 'strict laws' about them [Flanagan]
     Full Idea: Although everyone thinks cars and bodies obey the principles of causation, no one thinks it a deficiency that we don't know strict laws of automechanics or anatomy.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 65)
     A reaction: This attacks Davidson's claim that there are no strict psycho-physical laws, and I agree with Flanagan. Huge dreams of free will and human dignity are being pinned on the flimsy point that we have no strict laws here. But brains are very complicated.
17. Mind and Body / E. Mind as Physical / 3. Eliminativism
Physicalism doesn't deny that the essence of an experience is more than its neural realiser [Flanagan]
     Full Idea: One may be committed to the truth of physicalism without being committed to the claim that the essence of an experience is captured fully by a description of its neural realiser.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 90)
     A reaction: This is a reply to the Leibniz Mill question (idea 2109) about what is missing from a materialist view. Flanagan's point is that just as the essence of a panorama is the view from the hill, so the essence of consciousness requires you to be that brain.
18. Thought / A. Modes of Thought / 3. Emotions / f. Emotion and reason
Emotions are usually very apt, rather than being non-rational and fickle [Flanagan]
     Full Idea: One can question the idea that emotions are non-rational, fickle and flighty; on the contrary, emotions normally seem to be very apt.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 16)
     A reaction: This is the modern view of emotion which is emerging from neuroscience, which is greatly superior to traditional views, apart from Aristotle, who felt that wisdom and virtue arose precisely when emotions were apt for the situation.
18. Thought / A. Modes of Thought / 6. Judgement / a. Nature of Judgement
Judgement is always predicating a property of a subject [Beall/Restall]
     Full Idea: All judgement, for Kant, is essentially the predication of some property to some subject.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.5)
     A reaction: Presumably the denial of a predicate could be a judgement, or the affirmation of ambiguous predicates?
19. Language / C. Assigning Meanings / 2. Semantics
Semantics as theory of meaning and semantics as truth-based logical consequence are very different [Soames]
     Full Idea: There are two senses of 'semantic' - as theory of meaning or as truth-based theory of logical consequence, and they are very different.
     From: Scott Soames (Why Propositions Aren't Truth-Supporting Circumstance [2008], p.78)
     A reaction: This subtle point is significant in considering the role of logic in philosophy. The logicians' semantics (based on logical consequence) is in danger of ousting the broader and more elusive notion of meaning in natural language.
19. Language / C. Assigning Meanings / 6. Truth-Conditions Semantics
Semantic content is a proposition made of sentence constituents (not some set of circumstances) [Soames]
     Full Idea: The semantic content of a sentence is not the set of circumstances supporting its truth. It is rather the semantic content of a structured proposition the constituents of which are the semantic contents of the constituents of the sentence.
     From: Scott Soames (Why Propositions Aren't Truth-Supporting Circumstance [2008], p.74)
     A reaction: I'm not sure I get this, but while I like the truth-conditions view, I am suspicious of any proposal that the semantic content of something is some actual physical ingredients of the world. Meanings aren't sticks and stones.
19. Language / C. Assigning Meanings / 8. Possible Worlds Semantics
We can rest truth-conditions on situations, rather than on possible worlds [Beall/Restall]
     Full Idea: Situation semantics is a variation of the truth-conditional approach, taking the salient unit of analysis not to be the possible world, or some complete consistent index, but rather the more modest 'situation'.
     From: JC Beall / G Restall (Logical Pluralism [2006], 5.5.4)
     A reaction: When I read Davidson (and implicitly Frege) this is what I always assumed was meant. The idea that worlds are meant has crept in to give truth conditions for modal statements. Hence situation semantics must cover modality.
19. Language / D. Propositions / 1. Propositions
Propositions commit to content, and not to any way of spelling it out [Beall/Restall]
     Full Idea: Our talk of propositions expresses commitment to the general notion of content, without a commitment to any particular way of spelling this out.
     From: JC Beall / G Restall (Logical Pluralism [2006], 2.1)
     A reaction: As a fan of propositions I like this. It leaves open the question of whether the content belongs to the mind or the language. Animals entertain propositions, say I.
20. Action / C. Motives for Action / 3. Acting on Reason / b. Intellectualism
Intellectualism admires the 'principled actor', non-intellectualism admires the 'good character' [Flanagan]
     Full Idea: There are two main pictures of the good person: there is the 'good character', and there is the 'principled actor'. ..The first picture is non-intellectualist, and the second is intellectualist.
     From: Owen Flanagan (The Problem of the Soul [2002], p.145)
     A reaction: The second ideal elevates the principle itself above the actor who carries it out. Presumably consistency is a virtue, so a good character will at least pay some attention to principles. A good magistrate comes out the same in both views.
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / e. Ethical cognitivism
Cognitivists think morals are discovered by reason [Flanagan]
     Full Idea: Cognitivists think morals are discovered by reason.
     From: Owen Flanagan (The Problem of the Soul [2002], p.301n)
     A reaction: I take cognitivism to be (strictly) the view that morals are knowable in principle. Our intellects might not be up to the task (and so we might have to ask the gods what is right). There is also the possibility that morals might be known by intuition.
22. Metaethics / B. Value / 2. Values / a. Normativity
Ethics is the science of the conditions that lead to human flourishing [Flanagan]
     Full Idea: Ethics is the normative science that studies the objective conditions that lead to flourishing of persons.
     From: Owen Flanagan (The Problem of the Soul [2002], p. 17)
     A reaction: This is a nice slogan for the virtue theory account of the nature of ethics. I think it is the view with which I agree. I am intrigued that he has smuggled the word 'science' in, which is a nice challenge to conventional views of science.
29. Religion / A. Polytheistic Religion / 3. Hinduism
The Hindu doctrine of reincarnation only appeared in the eighth century CE [Flanagan]
     Full Idea: The doctrine of a cycle of rebirths and reincarnations that are normally required before one achieve nirvana was only proposed in the eighth century CE, and then spread like wildfire among Hindus and, to a lesser extent, among Buddhists.
     From: Owen Flanagan (The Problem of the Soul [2002], p.166n)
     A reaction: Intriguing. Plato had proposed it in the fourth century BCE. Presumably Hindus had always been dualists, and then suddenly saw and exciting possibility that followed from it. The doctrine strikes me as (to put it mildly) implausible.
29. Religion / D. Religious Issues / 2. Immortality / b. Soul
The idea of the soul gets some support from the scientific belief in essential 'natural kinds' [Flanagan]
     Full Idea: The idea of the soul could be easily trashed if science does not countenance essences, but science does countenance essences in the form of what are known as 'natural kinds' (such as water, salt and gold).
     From: Owen Flanagan (The Problem of the Soul [2002], p.181)
     A reaction: The existence of any essences at all does indeed make the existence of a soul naturally possible, but scientific natural kinds are usually postulated on a basis of chemical stability. Animals, for example, are no longer usually classified that way.