Abstract
A number of philosophers defend naturalistic moral realism by appeal to an externalist semantics for moral predicates. The application of semantic externalism to moral predicates has been attacked by Terence Horgan and Mark Timmons in a series of papers that make use of their “Moral Twin Earth” thought experiment. In response, several defenders of naturalistic moral realism have claimed that the Moral Twin Earth thought experiment is misleading and yields distorted and inaccurate semantic intuitions. If they are right, the intuitions generated by Moral Twin Earth cannot be appealed to in arguments against externalist moral semantics. The most developed case against the Moral Twin Earth argument that follows this strategy is found in a paper by Stephen Laurence, Eric Margolis and Angus Dawson. Here I argue that their attack on the Moral Twin Earth thought experiment fails. Laurence, Margolis and Dawson have not shown that we have reason to distrust the semantic intuitions it generates
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Notes
The distinction between natural and non-natural properties is notoriously difficult to get at with any precision. Most characterizations of the distinction focus on epistemological differences between properties of these kinds. Brink, for example, writes that, in contrast with non-natural facts and properties, “[n]atural facts and properties are presumably something like those facts and properties as picked out and studied by the natural and social sciences (broadly conceived)…” (1989: 22; cf. Timmons 1999: 12).
We can suppose this only if we deny that that the meaning of a predicate is to be identified with its intension. Brink rejects the identification of meaning with intension in his (1989: Chapter 6). See note 10 below.
For those who take co-intensionality to be sufficient for property identity, this necessity claim can be construed as expressing an a posteriori property identity.
Boyd goes on to characterize the relevant causal mechanisms: “Such mechanisms will typically include the existence of procedures which are approximately accurate for recognizing members or instances of k (at least for easy cases) and which relevantly govern the use of t, the social transmission of certain relatively approximately true beliefs regarding k, formulated as claims about t […], a pattern of deference to experts on k with respect to the use of t, etc. […]” (ibid.).
Here I use ‘internal’ where others might use ‘narrow’. An individual’s narrow mental states are typically understood as those mental states that the individual shares with all of her intrinsic duplicates. Some have noticed that, on this construal, it isn’t clear that an Earthling and his Twin Earth counterpart can have the same narrow mental states. The problem is that over half of the Twin Earthling’s body is presumably composed of XYZ molecules, whereas the same proportion of the Earthling’s body is composed of H2O molecules. If so, the two are not intrinsic duplicates, strictly speaking. Thus, they cannot have the same narrow mental states. In light of this, I prefer the somewhat less loaded ‘internal mental state’. This locution is meant to capture intuitively whatever kind of mental state Putnam intended each Twin Earthling to share with his or her Earthling counterpart in the 1750 story.
Putnam does not himself state the conclusion of the Twin Earth argument in terms of intensions. This may be because in “The Meaning of ‘Meaning’” he is thinking of intensions as “something like an individual speaker’s concept” (1975: 245, cf. 216–219). I am not using ‘intension’ in this way. I take intensions to be functions from worlds to extensions. The intension of a term need not be fixed by speakers’ concepts. If intensions are thought of as functions from worlds to extensions, then it follows that if two predicates have different extensions at any single world, they have different intensions.
That is to say, if there is a natural property N that uniquely causally regulates the actual use of ‘F,’ then the intension of ‘F’ is the function that maps each possible world to an extension containing all and only instances of N at that world.
By stipulating that moral properties are functional properties, H&T are following Brink’s suggestion in his (1984: 121f). There, Brink invokes a functionalist account of moral properties to explain the supervenience of moral properties on physical properties.
What justifies H&T in supposing that the essence of moral properties will be captured by theories in first-order normative ethics? The answer is that this is what SEN proponents have themselves claimed. Sturgeon, for example, writes, “If hedonistic act utilitarianism…turns out to be true, for example, then we can define the good as pleasure and the absence of pain, and a right action as one that produces at least as much good as any other…” (Sturgeon 1985: 61; cf. Brink 1989: 177f, 238, 2001: 162).
One reason to avoid casting the question as one about meaning is that Brink, for one, separates the meaning of a predicate from the property or intension it expresses. This is apparent in his rejection of “the semantic test of properties” (Brink 1989: 162, 166). He allows that a natural predicate could express the same property as a moral predicate even when the two predicates do not have the same meaning. Brink evidently thinks of the meaning of a predicate as something like a Fregean sense. On such a view, a predicate’s meaning is roughly a criterion for its application that speakers “associate” with that predicate. If this is the way meaning is to be construed, then it is immaterial to the defense of CSN whether ‘right’ has the same meaning (i.e., associated criterion of application) as t-‘right’. For this reason, I find it preferable to pose the present question as being about semantic content rather than meaning.
The standard organ harvest case involves a surgeon who kills one innocent healthy patient (without his consent) in order to transplant his organs to five other patients who would otherwise die.
H&T sketch a “generic” form of the MTE argument in their (2000). For a look at MTE in action against other proposed moral semantics see H&T (1996, 2000, Forthcoming).
Eric Gample makes the same point in his (1997: 152). See also Merli (2002). Merli argues that, if both Earthlings and Twin Earthlings separately achieve reflective equilibrium with respect to the question of which property regulates their use of ‘right,’ and further conversation will not move either from their normative theory, then “it seems increasingly reasonable to think that moralists and Twin-moralists would be warranted in interpreting each other as using different terms” (ibid. 228). Nevertheless, since both Tc and Td are epistemically possible for us, it still (incorrectly) appears to us as if the Earthlings and their Twins are having a substantive disagreement.
This example is inspired by David Copp’s (1990: 247f). I do not mean to attribute Tw to Nietzsche himself.
That is, the natural property whose functional essence is specified by Tw. Throughout this paper, I also use ‘Tc property’ and ‘Td property’ to denote the natural properties whose essences are specified by Tc and Td respectively.
Of course, the well-being of others may be indirectly relevant to the moral rightness of actions, given Tw. For example, there are likely to be situations in which an agent can express her will to power by forming alliances that benefit others.
Philippa Foot’s comments are especially relevant to the present discussion. In “Moral Arguments” she considers various criteria that a proposition must meet in order to be counted as a moral proposition. She is emphatic that whatever criteria is adopted, it must count Nietzsche’s doctrines as part of the subject matter of morality: “If a moral system such as Nietzsche’s has been refused recognition as a moral system, then we have got the criteria wrong…We recognize Nietzsche as a moralist because he tries to justify an increase in suffering by connecting it with strength as opposed to weakness, and individuality as opposed to conformity” (1958: 33).
In saying this, I am countenancing negative properties. Not everyone does so. I am uneasy about them myself. I help myself to negative properties here only because doing so makes it easier to see the basis for LM&D’s claim that Tc and Td properties exist on both planets. I believe their essential point could be made without appeal to negative properties. If not, and if negative properties really are indefensible, then so much the worse for LM&D.
Of course, it may be that many of the Twin Earthling acts that instantiate Td right-making properties also instantiate Tc right-making properties. But this should not trick us into taking Tc properties to play the same role on MTE that Td properties play there. The difference in their roles is revealed when we consider how Earthlings and Twin Earthlings, respectively, would behave in either actual or counterfactual cases where an action instantiates a Tc right-making property but not a Td right-making property (or vice versa).
For a review of psychological research that I believe lends empirical support to this speculation, see Richard Nisbett and Dov Cohen’s Culture of Honor (1996).
Or perhaps LM&D meant to suggest that readers cannot help but to assume that there is some other natural property that both Earthlings and Twin-Earthlings express by ‘right’, a property whose functional essence is captured neither by Tc nor Td. This hypothesis is addressed below in Sect. 7.
A more charitable hypothesis about how readers are likely to deal with this supposition is that they will simply assume that if Twin Earthlings want to refer to Earthling Tc right-making properties, they (the Twin Earthlings) will simply use a non-moral, natural property name (e.g., ‘maximizing utility’) rather than a moral term such as ‘rightness’. This hypothesis does no service for LM&D and is not addressed in their paper.
For his own part, Putnam simply adds the stipulation that on Twin Earth ‘aluminum’ names molybdenum and ‘molybdenum’ names aluminum. At first sight, it would appear that this stipulation is question begging, since he uses this case to conclude that ‘aluminum’ and t-‘aluminum’ have different extensions. However, Putnam’s interest in the aluminum example seems to be as a case where some members of each linguistic community know the underlying nature of the stuff they call ‘aluminum’ while others do not. If we needed to, the example could be modified so that no one on either planet knows enough chemistry to distinguish the two metals. The point presently being made would still stand.
Indeed, some philosophers actually have endorsed this reading of PTE, or something much like it. See for example Zemach (1976) and Mellor (1977). Though they do not use the language of functional properties, both philosophers maintain that the extension of ‘water’ as used on both planets includes both H2O and XYZ.
This reply to MTE is also suggested in Copp (2000), though Copp’s ideas about how the reply should be spelled out appear to be different from those of Kraemer and LM&D.
An alternative way of filling out the common core view is to say that the neutral theory characterizes the concept of rightness which in turn non-rigidly designates on each planet a distinct first-order natural property. This view would be similar to the account of ‘rational’ that Peter Railton explores in his (1993). H&T criticize Railton’s proposal in their (1996). They object that, when the functional characterization of rationality is made suitably neutral so as to avoid conceptual relativism, radical indeterminacy of reference results.
It may be worth noting that if, in fact, the intuition that ‘right’ and t-‘right’ express the same property is to be explained in this way, then we must accuse readers of ignoring H&T’s stipulation that a Tc property (i.e., maximizing utility) causally regulates the use of ‘right’ and a Td property (i.e., treating others as ends) causally regulates the use of t-‘right’. Readers must presume that it is the common higher-level functional property that causally regulates the use of both terms. It is not implausible that some readers might have overlooked H&T’s stipulations here. Purely causal theories of reference like Boyd’s face a well-known problem with referential indeterminacy: the so-called “qua-problem”. This indeterminacy may well give readers enough leeway to suppose that a common higher level property regulates the use of ‘right’ and t-‘right’. But this confusion should not be seen as impugning MTE. In my view, the fact (if it is a fact) that readers gravitate towards the higher-level property reading of MTE reveals how implausible it is to identify rightness with right-making natural properties as the proponents of SEN do (see note 9). For a statement of the qua-problem see Kim Sterelny (1983). Boyd addresses the qua-problem (though not by that name) in (1999: 58).
In their response to Copp, H&T make what is essentially the same observation (H&T 2000: 143).
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Acknowledgements
I am grateful for the input I received from Fred Feldman, Hilary Kornblith, Helen Majewski, Sam Cowling and an anonymous referee.
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Rubin, M. Sound intuitions on Moral Twin Earth. Philos Stud 139, 307–327 (2008). https://doi.org/10.1007/s11098-007-9118-8
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DOI: https://doi.org/10.1007/s11098-007-9118-8