Monday, July 9, 2018

Perdurance and consciousness

The standard perdurantist theory of consciousness is that the whole four-dimensional individual is derivatively conscious in virtue of the slices being non-derivatively conscious.

Here is a quick objection:

  1. A human-type pain needs to last more than a nanosecond to be noticed.

  2. A human-type pain needs to be noticed to exist.

  3. So, a human-type pain needs to last more than a nanosecond to exist.

  4. For an entity to host a pain that needs u units of time to exist, the entity needs to exist for u units of time.

  5. A momentary slice exists for less than a nanosecond.

  6. So, no momentary slice hosts a human-type pain.

(One can also try running a somewhat similar argument against presentism. There are interesting parallels between perdurantism and presentism.)

I think what the perdurantist needs to do is to deny 4, and hold that a momentary slice of the person is in pain because of what is going on with temporally neighboring slices. In other words, being in pain is not an intrinsic property of a momentary slice. Moreover, to avoid circularity or regress, our perdurantist has to say that the pain of a slice does not depend on the neighboring slices being in pain, but on some other state of the neighboring slices.

Thus, the view has to be that there have to be some more fundamental states of slices such that a slice is in pain in virtue of itself and its temporal neighbors being in those more fundamental states.

Corollary: A perdurantist must be a reductionist about qualia.

Many perdurantists are materialists and will be happy to embrace this corollary. But let’s think some more. If the conscious state of a momentary slice depends on the states of the slices and its neighbors, then the conscious states of momentary slices are not temporally (or otherwise) intrinsic. But now there are two problems. First, intuitively, conscious states are intrinsic. Indeed, they seem paradigms of intrinsic states. Second, the whole point of primarily attributing states to slices rather than to the four-dimensional whole was to solve the problem of temporal intrinsics. So once we see the conscious states as non-intrinsic, the motivation for attributing them to slices should disappear.

Thus, at this point it is very natural, I think, for the perdurantist to opt for a different theory of consciousness. Consciousness (and presumably the same thing goes for other mental properties) is a property of the four-dimensional whole, and it is had in virtue of the properties of slices—but non-conscious properties of slices. Whether this is plausible depends on how plausible it is to think consciousness is reducible to non-conscious states.


Brian Cutter said...

Interesting. So there are three things to consider: (i) the whole 4D person, with a temporal extent of (say) 80 years, (ii) the "thin" time-slices (i.e. the 3d instantaneous temporal parts), and (iii) the "thick" time-slices, with a temporal extent of u units of time. Couldn't the perdurantist hold that consciousness is a primitive irreducible property of thick time-slices, then say that a person is (derivatively) conscious at a time just in case that person has a conscious thick time-slice that exists at that time? (We could also say that a thin slice is derivatively conscious when it is a part of a conscious thick slice.)

Maybe there are still some strange consequences. The temporary intrinsics argument relies on the intuition that 3D shape is a monadic property, not a relation to times. The corresponding intuition about pain seems to be just as strong. But then it's natural to say the same about the conjunction of 3d shapes and phenomenal properties, e.g., being human-shaped-and-in-pain. But notice that on the above view, nothing will be human-shaped-and-in-pain *simpliciter*, since whatever is human-shaped simpliciter is 3-dimensional and whatever is in pain simpliciter is 4-dimensional.

Alexander R Pruss said...


The thick slice suggestion is one way to go, but I think there are problems beyond the one you note:

1. Consider such a thick slice. Consider a time t1 half a nanosecond from the beginning of the thick slice. Either it is hurting at t1. If it is not hurting at t1, then the problem of temporary intrinsics comes up for the thick slice, as it is hurting at some times but not others. So, suppose the thick slice is hurting at t1. But now here is something that seems obvious: Whether there is pain at t1 does not depend on what happens after t1. So, imagine a possible world where the thick slice is annihilated half a nanosecond after t1. The pain must still be there. But now a one-nanosecond slice is in pain, which is impossible as pain needs more than a nanosecond.

2a. It is unlikely that we would get well-foundedness of pain. Plausibly, for any thick slice in pain, a slightly thinner slice would be in pain as well.

2b. If I am in pain at t1, there are many slices that are in pain at t1: there is the whole worm, there is a year-long slice containing t1, there is a one-month slice containing t1, and there are infinitely many u-thick slices. This seems to be a vast multiplication of pains. Now, the usual way for the perdurantist to handle such multiplication is to distinguish between derivative and non-derivative possession. So, the whole worm and the year-long slice are only derivatively in pain. But then there must be slices non-derivatively in pain. Now raise the 2a worry about them.

3. This worry is a little vague. Consider two thick slices of the same thickness that overlap by some large amount, say 90%. I have a pain episode in virtue of each slice. But is it the same episode or a different one? Neither answer seems quite right.

Brian Cutter said...

The well-foundedness issue is interesting. They could just say there's an arbitrary precise temporal duration, e.g. 1.45624 milliseconds, such that primitive phenomenal properties non-derivatively attach only to slices with that precise thickness. This seems like a pretty unattractive view, but arguably any dualist will need similarly arbitrary parameter values in their psychophysical laws (e.g., specifying precisely what patterns of physical activity produce consciousness). I think the well-foundedness problem arises generally for any view (or at least any non-reductive view) that combines subject materialism (the view that the bearers of phenomenal properties are material objects) with a permissive ontology. The perdurantist is permissive about temporal parts, with the result that there's no non-arbitrary temporal length of a minimal bearer of consciousness. Likewise, even if we don't believe in temporal parts, if we're permissive about spatial parts, it will be hard to find a smallest spatial part to be the bearer of consciousness. (E.g., if my brain is fit to be a subject of consciousness, then my brain minus an electron is also fit, and so on.)

Alexander R Pruss said...

Another one: Suppose that each thick slice hurts throughout its temporal duration. Suppose pains are non-derivatively had by slices of thickness 1. Now, consider the slices A and B corresponding to the time intervals [0,1] and [0.5,1.5], respectively. Now consider the pain at time 0.75. That pain is had non-derivatively by multiple two different slices, A and B. So we have too many non-derivative thinkers.

I am thinking that the best move might be to say that each thick slice hurts but only at its upper end. Thus, slice A hurts at t=1, and slice B hurts at t=1.5. But now there is change with respect to pain within a thick slice, as it hurts only for some of the time that it exists.