RobokkuSun, Jan 27, 2008 Spaceweaver: Yes, it can be difficult to engage with a topic like this in brief comments - that definitely clarifies things. Hope I came across OK. And what you say really resonates with my own way of looking at things. Lewis was crazy, which is admirable, but I'm not really a sympathiser, just wanted to fight his corner a little.
(I guess some version of the stock retort is still available to him, though: GMR provides working referents for modal language which allow the logic required for our normal discourse, and at a small ontological cost. Personally, I'd just foot the ontological bill, because, well, there just is loads of stuff.)
Anyway, back to the Modal Realism Consciousness idea. First of all, a bit of re-writing: in the mind theory (MIND 1-6), when we say "possible minds" I take it we we are talking about other minds, not minds in possible worlds. Otherwise, I don't see what's new compared to Modal Realism. Given that, "actual" in MIND 4 should be replaced with some sensible equivalent indexical - e.g., "me" or "my mind".
Now, MIND 5 raises some problems:
5. Possible Minds are unified by the spatiotemporal interrelations of their parts; possible Minds are spatiotemporally isolated from each other.
That second point first: if our minds are spatiotemporally isolated from each other, then they must be so isolated from the rest of the physical world, because of the transitivity of spatiotemporal relations. (If so, then causality between minds looks impossible, so MIND 6 holds.) However, I consider my mind to be simultaneous with the rest of the (present) world, and so, if other minds are alike, simultaneous with other minds. So minds are not temporally isolated as Lewis' worlds are.
The first point now: how is a mind unified? In the case of Lewis' worlds, it's the mere fact of spatiotemporal interrelations between parts that unifies, not any particular such relations. That is no good for minds, since we have seen that the relations hold between minds. Could it be some particular spatiotemporal relations that define a single mind? Not easily: the temporal relations are not enough on their own, since other minds can be concurrent, and if you do locate a mind in space then either it has some extension and you will rope in some physical matter (brain cells, knee cap - wherever you put it), or it is at a point and you will need a very good story about why it's at any particular point.
A possible answer:
Having said that, the best way to fit MIND 1-6 into a coherent story, seems to be to go for some kind of epiphenomenalism: have the mental supervene on the physical. Each mind could then be unified by its being caused by the same physical bits, those bits being unified by particular spatiotemporal interrelations and relations to other bits of the world.
Here's my re-write for the epiphenomenalists:
1. Other Minds exist and are equally real;
2. Other Minds are the same sort of things as my Mind — they differ in content, not in kind;
3. Other Minds cannot be reduced to something more basic — they are irreducible entities in their own right.
4. "My mind" is indexical. When I distinguish my Mind from others by claiming that it alone is mine, I mean only that it is mine — I live here. (OK, this is trivial now, but it kind of was in GMR.)
5. Other Minds are unified by the causal relations of their parts to physical matter and the spatiotemporal (inter)relations of that physical matter (to the rest of the world); Other Minds are spatially isolated from each other (bear no spatial relations to one another).
6. Other Minds are causally isolated from each other.
Spaceweaver: Yes, it can be difficult to engage with a topic like this in brief comments - that definitely clarifies things. Hope I came across OK. And what you say really resonates with my own way of looking at things. Lewis was crazy, which is admirable, but I'm not really a sympathiser, just wanted to fight his corner a little.
(I guess some version of the stock retort is still available to him, though: GMR provides working referents for modal language which allow the logic required for our normal discourse, and at a small ontological cost. Personally, I'd just foot the ontological bill, because, well, there just is loads of stuff.)
Anyway, back to the Modal Realism Consciousness idea. First of all, a bit of re-writing: in the mind theory (MIND 1-6), when we say "possible minds" I take it we we are talking about other minds, not minds in possible worlds. Otherwise, I don't see what's new compared to Modal Realism. Given that, "actual" in MIND 4 should be replaced with some sensible equivalent indexical - e.g., "me" or "my mind".
Now, MIND 5 raises some problems:
That second point first: if our minds are spatiotemporally isolated from each other, then they must be so isolated from the rest of the physical world, because of the transitivity of spatiotemporal relations. (If so, then causality between minds looks impossible, so MIND 6 holds.) However, I consider my mind to be simultaneous with the rest of the (present) world, and so, if other minds are alike, simultaneous with other minds. So minds are not temporally isolated as Lewis' worlds are.
The first point now: how is a mind unified? In the case of Lewis' worlds, it's the mere fact of spatiotemporal interrelations between parts that unifies, not any particular such relations. That is no good for minds, since we have seen that the relations hold between minds. Could it be some particular spatiotemporal relations that define a single mind? Not easily: the temporal relations are not enough on their own, since other minds can be concurrent, and if you do locate a mind in space then either it has some extension and you will rope in some physical matter (brain cells, knee cap - wherever you put it), or it is at a point and you will need a very good story about why it's at any particular point.
A possible answer:
Having said that, the best way to fit MIND 1-6 into a coherent story, seems to be to go for some kind of epiphenomenalism: have the mental supervene on the physical. Each mind could then be unified by its being caused by the same physical bits, those bits being unified by particular spatiotemporal interrelations and relations to other bits of the world.
Here's my re-write for the epiphenomenalists:
- 1. Other Minds exist and are equally real;
- 2. Other Minds are the same sort of things as my Mind — they differ in content, not in kind;
- 3. Other Minds cannot be reduced to something more basic — they are irreducible entities in their own right.
- 4. "My mind" is indexical. When I distinguish my Mind from others by claiming that it alone is mine, I mean only that it is mine — I live here. (OK, this is trivial now, but it kind of was in GMR.)
- 5. Other Minds are unified by the causal relations of their parts to physical matter and the spatiotemporal (inter)relations of that physical matter (to the rest of the world); Other Minds are spatially isolated from each other (bear no spatial relations to one another).
- 6. Other Minds are causally isolated from each other.
Is it still interesting?