Tuesday, January 12, 2010

Tallis's Time-travel Argument Against Physicalism

Most of the arguments that appear in Ray Tallis's "You won't find consciousness in the brain" were old news to me, but at least one of them I hadn't heard of before. In brief, it goes like this:
1. No neural/physical state can reach into the past or future.
2. Consciousness can reach into the past or future.
Therefore, you won't find consciousness in the brain.
Take that, brain lubbers!

I leave it as an exercise for readers to come up with an unequivocal reading of this stuff about reaching that can make one of the premises plausible without rendering the other one insane.

The relevant passage from the article is this:

And there is an insuperable problem with a sense of past and future. Take memory. It is typically seen as being "stored" as the effects of experience which leave enduring changes in, for example, the properties of synapses and consequently in circuitry in the nervous system. But when I "remember", I explicitly reach out of the present to something that is explicitly past. A synapse, being a physical structure, does not have anything other than its present state. It does not, as you and I do, reach temporally upstream from the effects of experience to the experience that brought about the effects. In other words, the sense of the past cannot exist in a physical system. This is consistent with the fact that the physics of time does not allow for tenses: Einstein called the distinction between past, present and future a "stubbornly persistent illusion".
h/t to @dweisk for putting this gem on my radar.