2. Causal Discernment of Properties. Initial statement.  (Note that this is ambiguous between mental property needing to have (i) some effects (in order to ward off epiphenomenalism) and (ii) new effects, not ascribe/ascribable to previously recognized factors.)

"This we may call "Alexander's dictum": To be real is to have causal powers."
(N'sTwMC: p. 348)

"I am supposing that a nonreductive physicalist is a mental realist, and that to be a mental realist, your mental properties must be causal properties  properties in virtue of which an event enters into causal relations it would otherwise not have entered into. (MoNRM: 279)"

[Note 9/15/01: Kim is in this quote not endorsing a counterfactual account of causation -- his concept of causation in fact remains unanalyzed.  What he's saying here is that to be realist about a property is to hold that it brings new 'causal powers'.  The problem for Kim will be stating this concept of newness in a counterfactual way that doesn't also lead to an attack on the base properties.]

Alexander’s Dictum: Each property must have some effect(s).  (Methodologically: there is no reason to postulate, or for our theory to recognize the existence of, a property that has no effects.)

Against Davidson’s anomalous monism:

On anomalous monism, that an event falls under a given mental kind is a causally irrelevant fact; it is also something that is entirely inexplicable in causal terms.  Given all this, it's difficult to see what point there is in recognizing mentality as a feature of the world (MoNRM: 270).

Here, the principle of causal discernment is brought against “mental kinds” by way of accusing these kinds of  epiphenomenalism: mental kinds are, we are told, “causally irrelevant” and “entirely inexplicable in causal terms”; and given this, there is no point in even postulating (theoretically “recognizing”) mental properties (or “kinds”).

[9/15/01: Here, with his (implicit) accusation of epiphenomenalism, Kim is objecting to mental properties having *no* causal powers on Davidson's scheme.  This will be blocked by Alexander's dictum, so long as (trivially) mental states are taken by Davidson to be real..]

"[Principle of Causal Individuation of Kinds] Kinds in science are individuation on the basis of causal powers; that is, objects and events fall under a kind, or share in a property, insofar as they have similar causal powers."
(MR&MoR: p. 326)

Causal Discernment of (Scientific) Properties: If Property A and Property B have exactly the same effects, then they are the same property.  (Methodologically: if there is no causal reason to postulate that A and B are two different properties  i.e., if they are causally indiscernible, there is no reason to postulate that A and B are two distinct properties.)

Physical Realization Thesis

Causal Irreducibility of the Functional

"[The Causal Inheritance Principle] If mental property M is realized in a system at t in virtue of physical realization base P, the causal powers of this instance of M are identical with the causal powers of P."
(MR&MoR: p. 326)

why we should accept the CI principle:
"...to deny it would be to accept emergent causal powers: causal powers that magically emerge at a higher level and of which there is no accounting in terms of lower-level properties and thier causal powers and nomic connections.  This leads to the notorious problem of "downward causation" and the attendant violation of the causal closure of the physical domain."
(MR&MoR: 326-7)

"It is clear that the Causal inheritance Principle, in conjunction with the Physical Realization Thesis, has the consequence that mental kinds cannot satisfy the Causal Individuation Principle, and this effectively rules out mental kinds as scientific kinds.  The reasoning is simple: instances of M that are realized by the same physical base must be grouped under one kind, since ex hypothesi the physical base is a causal kind; and instances of M with different realization bases must be grouped under distinct kinds, since, again ex hypothesi, these realization bases are distinct as causal kinds.  Given that mental kinds are realized by diverse physical causal kinds, therefore, it follows that mental kinds are not causal kinds, and hence are disqualified as proper scientific kinds."
(MR&MoR: 327)

[9/15/01: Here Kim has crossed the line.  Unless mental property M brings *new* effects (causal powers), it is not real.

Also: why all this is methodological in the end: I don't see how Kim -- or anyone else -- could argue the impossibility of 'noumenal', totally non-causal properties.  What Kim seems to be driving at is rather that we have no reason to premise such properties in our theories, specifically  our scientific theories.]

[instances of M that are realized by the same physical base must be grouped under [at least] one kind [my -- crucial -- addition]

"...I find the following principle highly plausible (I have elsewhere called it "the causal inheritance principle"):

If a second-order property F is realized on a given occasion by a first-order property H (that is, if F is instantiated on a given occasion in virtue of the fact that one of its realizers, H, is instantiated on that occasion), then the causal powers of this particular instance of F are identical with (or are a subset of) the causal powers of H (or of this instance of H)."
(Kim 1998: 54)

[Here Kim specifically allows a mental property to have only a subset of    the base's effeect/causal powers.]

[But here Kim lapse into the stronger, “novel effects” reading of Alexander’s dictum:]

"...as we have observed, the emergentist and the nonreductive physicalist are mental realists, and Mental Realism, via Alexander's dictum, entail causal powers for mental properties.  ...Now, mental properties, on both positions, are irreducible net additions to the world.  And this must mean, on Alexander's dictum, that mental properties bring with them new causal powers, powers that no underlying physical-biological properties can deliver. For unless mentality made causal contributions that are genuinely novel, the claim that it is a distinct and irreducible phenomenon over and beyond physical-biological phenomena would be hollow and empty."
(N'sTwMC: p. 350)

[NB: “causal power” = “ causal contribution”]

[9/17/01: This is a nice quote: unless the mental properties bring novel “causal contributions,” “the claim that it is a distinct and irreducible phenomena... would be hollow and empty”.  It is not certain what Kim means by “hollow and empty,” but I suggest it is uncontroversial that he intends such a claim to not merit inclusion in our scientific theories.  But it doesn’t follow from the principles accepted so far (see below): the mental property has some effect (some “causal power”), so it is real by Alexander’s Dictum; it doesn’t have exactly the same set of effects (“causal powers”) as any of its instantiating base properties, so it is (causally) distinct and irreducible, according to the Principles of Causal Discernment and Causal Irreducibility.  So why does Kim think it follows so self-evidently that such a mental property is not a real, distinct, and irreducible property?  What is the missing extra principle leading him to what seems to be exactly the wrong conclusion? 

While my answer must be reconstructive, and so at least minimally speculative, I would point out that one simple addition here would yield exactly the result Kim claims.  What we add here is the further methodological principle that the only reason for a theory to include recognition of an object – or property – is if it causally accounts for some phenomenon not already causally explicable by other objects or properties in the theory.  Such a principle states, in brief, that the only methodological reason for including anything in a scientific theory is that it has some effect(s) not already attributed to something else in that theory.  Call this “The Principle of Causal Methodology”.

Principle of Causal Methodology: The sole reason to postulate an object or property in a scientific theory is because that object or property would causally account for some effect(s) not causally accounted for by any of the other objects or properties in the theory. 

The Principle of Causal Methodology says, in effect, that there is no reason for science to recognize the existence of anything, except to account for hitherto inexplicable phenomena.  This looks deceptively like the (much weaker) principle we called Alexander’s Dictum (and their similarity may be why Kim takes the trouble to cite Alexander’s Dictum repeatedly, and then to repeatedly draw his conclusion shortly thereafter).  But Alexander’s Dictum says: There is no reason for science to recognize the existence of a property that has no causal effects in the world; the Principle of Causal Methodology states instead that there is no reason for science to recognize the existence of a property that has no novel causal effects in the world.  Alexander’s Dictum only rules out properties which are entirely devoid of any effects (otherwise inexplicable or not); whereas the Principle of Causal Methodology holds that the sole function of science, and scientific theory (and hence the sole standard for scientific theory choice) is novel causal explanation.

Now, if we accept the Principle of Causal Methodology, we would immediately derive exactly the result Kim foresees: since mental properties cannot bring any new causal effects – on pain of violating the causal closure of the physical – the Principle of Causal Methodology legislates that mental properties not be a part of scientific theory at all.

[And so long as Kim does not block alternate methodological points of entry for properties, along the lines of the Principle of Causal Methodology, he cannot reach his conclusion from the above premises.]

Of course, Kim has given no reasons whatsoever for believing the Principle of Causal Methodology – he nowhere even recognizes explicitly the need for such a principle in his argument.  More importantly, it is a view which functionalists have explicitly disavowed for decades.  For contemporary functionalists, the primary reason for postulating irreducible functional properties was that these properties allow simple, general regularities (or “laws”) in our theories that span various physical bases, and hence bring increased unification of otherwise disparate phenomena.  So Putnam states:

At around the same time, Fodor, in a landmark article, presents exactly the same defense of functional properties:

And more recently, Jackson and Pettit, in a discussion of functionalist epiphenomenalism, provides the same motivation for functionalist theory:

Now, while it may be a methodological merit for a theory to provide causal accounts of phenomena, this nowhere bars admitting that simplicity, generality, and unification are additional methodological criteria.  But the point of the Principle of Causal Methodology is precisely to deny this: for that principle specifically denies that there can be any other motive for accepting properties, objects, or other structure into our theories.

[Alternately, we could put the point like this: what we give causal explanations of are individual events – the “effects” we are tallying in Kim’s discussion of “causal power” are specific phenomena.  Although Kim more than once appeals to laws as constituting the essence of science and scientific theory (Kim : ), Kim’s discussion of methodology, with its emphasis on causal explanation, seems to neglect questions of methodology for postulating and accepting generalization, regularities, or “laws”.  And perhaps only that could explain why the Principle of Causal Methodology could seems like an adequate account of scientific methodology, even in its most general outline.] 

Suppose functional property A is instantiated in a set of base properties B1,..., Bn.  We require (i) that this set of base properties be non-empty (since, on the physicalist functionalist account, each instance of a functional property must be instantiated in some or another physical property.  (ii) If there is more than one property in the base set, then any two base properties Bi and Bj, being distinct properties, must differ causally in some respect (straightforwardly, from the Weak causal discernment of properties).  Already, then, we can establish that the functional property A cannot be causally indiscernable from more than one base property Bi in the set. (That is, A cannot be causally indiscernable from two distinct base properties Bi and Bj, since we have just established that Bi and Bj, being distinct properties, are themselves causally discernible.)  

So A is causally indiscernable from at most one base property Bi.  But finally, the functionalist has adopted, from the outset, the assumption that functional properties do not reduce to any of its base properties.  Run through these assumption about causal discernibility -- and assuming, with Kim, that causally indiscernible properties collapse, or *reduce*, one to the other --  we strengthen that finally result a bit, to state that that (iii) A is causally discernible from every one of its base properties Bi.  Call that principle "The Causal Irreducibility of the Functional" (the irreducibility of the functional, stated in terms of causal discernment).
From this result, and the Weak Principle of Causal Discernment, we then see that (iv) for each base property Bi, either A has some effect which Bi does not, or Bi has some effect that A does not.  Kim argues that the first disjunct is unacceptable -- that in each instance the functional property A cannot have any further effects (any more "causal power") than its instantiating base property Bi.  Suppose we accept this claim. Then we have blocked the left disjunct of (iv), leaving only the right one: (v) for each base property Bi, Bi has some effect that A does not.

With the admission of (v), Kim is confident of having banished non-reducing functional properties from science.  For, 

[footnote to subsection on simplicity: We could also pose a dilemma for Kim here: if simplicity and parsimony are relevant methodological principles in this debate, then my reliance on Weaker principles (of Causal Exclusion and Causal Discernment of Properties) should constitute prima facie evidence in favor of my view over Kim's.  On the other hand, if Kim dismisses the advantages of my weaker assumption, that provides prima facie evidence against simplicity and parsimony being relevant methodological constraints in this debate.]

Principles of Causal Discernment:

1. Alexander’s Dictum: Each property must have some effect(s).  (Methodologically: there is no reason to postulate, or for our theory to recognize the existence of, a property that has no effects.)
2a. Causal Discernment of (Scientific) Properties: If Property A and Property B have exactly the same effects, then they are the same property.  (Methodologically: if there is no causal reason to postulate that A and B are two different properties  i.e., if they are causally indiscernible  there is no reason to postulate that A and B are two distinct properties.)

2b. Principle of Novel Effects.  Each property must have some new effect(s)  i.e., must have some effects that no other property (or family of properties) has.  (Methodologically: if a property A has only effects already theoretically attributed to properties B1...Bn, then there is no reason to postulate the existence of A, in addition to B1...Bn.)

Kim has given us reasons to hold 1 and 2a; but 2b does not follow from these.  It is an additional methodological constraint on theory construction (and scientific ontology).

Now, it might well appear that 2b follows directly from 2a: To postulate the existence of any property is, by 1, to postulate that the property has some effects. And if A is none of B1...Bn, then by 2a A must not have exactly the same effects of any of the B1...Bn.  But that in itself does not imply that A has an effect that none of the B1...Bn have.  A's having an effect that none of the B1...Bn have would certainly be *one* way of making these claims true; but not the only way.  So 2b is consistent with the conjunction of 1 and 2a, but 2b does not *follow* from it.  

What reason has Kim offered us to believe 2b, above and beyond 1 and 2a?  Kim might argue that the methodological phrasing of 2b brings out especially obviously why we should believe it: if we already believe in the existence of B1...Bn -- and so have attributed effects to B1...Bn -- then we have no methodological reason to then postulatein addition property A.  We wouldn't so the story would go, have any reason to postulate A, because no effects so far causally unaccounted for would be accounted for by a new, slightly bigger theory made by adding (claim to the existence of) property A to the previous theory.