Metaphysics of quantity and the limit of phenomenal concepts

Abstract

Quantities like mass and temperature are properties that come in degrees. And those degrees (e.g. 5 kg) are properties that are called the magnitudes of the quantities. Some philosophers talk about magnitudes of phenomenal qualities as if some of our phenomenal qualities are quantities. The goal of this essay is to explore the anti-physicalist implication of this apparently innocent way of conceptualizing phenomenal quantities. I will first argue for a metaphysical thesis about the nature of magnitudes based on Yablo’s proportionality requirement of causation. Then, I will show that, if some phenomenal qualities are indeed quantities, there can be no demonstrative concepts about some of our phenomenal feelings. That presents a significant restriction on the way physicalists can account for the epistemic gap between the phenomenal and the physical. I’ll illustrate the restriction by showing how that rules out a popular physicalist response to the Knowledge Argument.

Keywords:

• Quantity
• Proportionality of causation
• phenomenal concept strategy

Notes

¹ I received a lot of help writing this paper. I couldn’t thank Ross Cameron enough for not only commenting on an earlier draft of this paper but also agreeing to supervise my dissertation that grew out of the ideas in this paper. I’m very grateful to Harold Langsam for his extensive comments and suggestions about my arguments, and for convincing me that there is something worth pursuing in the very first version of this paper. My gratitude also goes to James Cargile, Matt Duncan, Brie Gertler, Trenton Merricks, Andrew Morgan, Walter Ott, and Nick Rimell for patiently commenting on numerous versions of this paper; those conversations and feedback pushed me to think about the issue harder and articulate my reasoning more clearly. And, this paper wouldn’t have been half as readable as it is without Stacie Thyrion’s generous help in tidying up my English. Finally, I would like to thank my audience for their valuable comments when I presented earlier drafts of this paper at Vrije Universiteit Amsterdam and Cambridge University and the anonymous reviewer of this journal for very helpful suggestions.

² The reductive, nominalist theory of quantity is developed in Ellis (1966), Forge (1987), Bigelow and Pargetter (1988), and recently Dasgupta (2013). For the difficulties of a nominalist theory of quantity and various ways in which a theory of quantity based on magnitude realism can be developed, see for instance Swoyer (1987), Mundy (1987), Armstrong (1988), and Eddon (2013).

³ It is perhaps worth noting that the determinable–determinate relation has nothing to do with the type-token (or universal-particular) distinction. A maximally determinate property of a determinable property is still a type or universal that can be instantiated in multiple instances.

⁴ Even if we set the idea of cognitive phenomenology aside, whether or not all non-cognitive phenomenal qualities come in degrees, and are therefore quantities, is debatable. That is why I am making a weaker claim here. Among other things, the issue depends on what we think can be represented in our sensory experience. I am skeptical, but if, like Siegel (2010), one thinks that our visual experience can have content about, for instance, causation, and there is a causation-quale for that, such causation-quale does not seem to come in degrees, unlike the quale for pain and heat.

⁵ My thoughts on a layered reality and the proportionality requirement of causation have benefited from comments and discussions with Ross Cameron and Trenton Merricks.

⁶ In Yablo (1992), he argues that determinables and determinates do not compete in doing causal work. They are both causes of an effect (see also Wilson (2009). In Yablo (1997), however, he thinks that there is competition. And he argues that wide mental states usually win the competition to be the cause of our actions even though the local brain states are still causally relevant.

⁷ E.g. Shapiro and Sober (2012) recently argue against both the metaphysical and pragmatic version of the proportionality constraint (what I call a metaphysical requirement here, they call it semantic). But I am not convinced by their argument. Shapiro & Sober’s argument seems to require the subjunctive conditional claim ‘if not-p, then q’ to mean it is impossible that not-p and q. But that is just false. The subjective conditional ‘if not-p, then q’ just means at the nearest possible worlds where not-p, q is also true at those worlds. Their counterexamples against proportionality do not seem to work once we agree to evaluate subjective conditionals by examining only the nearest possible worlds instead of all possible worlds. In any case, this is a debate for another occasion.

⁸ I would like to thank Brie Gertler for pressing me very hard on this point.

⁹ I couldn’t emphasize enough how much this section benefits from the wonderful mix of encouraging comments and razor-sharp objections from Harold Langsam.

¹⁰ I use <x> to signify the concept of x. And italic is reserved for properties, e.g. being massive.

¹¹ Notice that being 100.1 kg is not a more determinate way to have mass. It is a different maximally determinate way to have mass.

¹² One alternative suggestion that has been presented to me is, although there is only one pain that I feel, which property in the determinable–determinate hierarchy my phenomenal feeling is depends on the attention of the pain sufferer. An undesirable consequence of this suggestion is that it seems we have to say that as long as I am not paying attention, I will feel just a pain determinable while there are some more specific pains that I instantiate without feeling them. Furthermore, it also seems to me that whether a mental property is a phenomenal feeling or not should be intrinsic to that mental property and not subject to contingencies like shift of attention. I think the way I model phenomenal feelings upon magnitudes like temperatures gives us a very neat way to organize all the intuitions we have about phenomenal feelings.

¹³ Notice that this talk of ‘additional mental properties’ does not contradict the fact that we instantiate being very painful in virtue of instantiating a magnitude of pain.

¹⁴ Phenomenal concepts understood in this way are also called recognitional concepts in the literature. For other defenders of this approach, see Tye (2000; 2003) and Carruthers (2004). Tye now renounces the phenomenal concept strategy (2009).

¹⁵ The usual thought is that once the reference of simple concepts is naturalized, we can explain reference of complex concepts with compositionality. For examples of attempts to naturalize simple mental representations, see Dretske (1981, 1988), Fodor (1987), Rupert (1999, 2001), Price (2001), Ryder (2004), etc.

¹⁶ Notice that this does not imply that phenomenal feelings have no causal power. Given what I have argued in this essay, my pain can still cause my enemy’s pleasure (or my sadness) – for pleasure (or sadness) is a quantity that comes in degrees. And causal relations among various quantities appear to be exactly the kind of thing mathematical laws of nature purport to capture. I will leave causation among magnitudes of different quantities for another occasion. Neither does my argument imply that we cannot think about our phenomenal feelings at all; even a physicalist should not think that mental reference can only be established by a causal relation between a mental representation (e.g. a concept) and the referent. My argument only challenges the possibility of demonstratives about our phenomenal feelings.

¹⁷ I would like to thank an anonymous reviewer for bringing some of the potential objections in this section to my attention.

¹⁸ Of course, one can stipulate that I have a demonstrative concept that refers to the average temperature in that period. But such stipulations are made purely on pragmatic grounds. There is no epistemic reason for thinking that a demonstrative concept <this temperature> is about the average temperature instead of the average plus 0.001 degree Fahrenheit.

¹⁹ See also Ball (2009) for another recent attempt to argue that there is no such thing as phenomenal concepts.