The problem with the paragraph is that the referent of it changes midway.
In an attempt to demonstrate the problem, I will fully expand all instances of it and its in the examples I provide.
If the referent remains the same throughout, then it would be interpreted in the following fashion:
- ✘ It = the possibility that none of the people around you may be conscious
✘ To consider [the possibility that none of the people around you may be conscious] produces an uncanny feeling. On the one hand [the possibility that none of the people around you may be conscious] seems conceivable, and no evidence you could possibly have can rule [out] [the possibility that none of the people around you may be conscious] decisively. On the other hand [the possibility that none of the people around you may be conscious] is something you can't really believe is possible: your conviction that there are minds in those bodies, sight behind those eyes, hearing in those ears, etc., is instinctive. But if [the power of] [the possibility that none of the people around you may be conscious] comes from instinct, is [the possibility that none of the people around you may be conscious] really knowledge? Once you admit the possibility that the belief in other minds is mistaken, don't you need something more reliable to justify holding on to [the possibility that none of the people around you may be conscious]?
However, that doesn't make sense. If you admit that the belief in other minds is mistaken, then you wouldn't need anything else to justify "the possibility that none of the people around you may be conscious."
As such, the referent of it has to be changing midway through the paragraph. While the change in the referent has the paragraph make sense, this also results in confusing reading—because you have to struggle to forget about the previous referent of it.
Normally, the referent of a pronoun does not change midway through a paragraph.
Following is the likely change in the referent:
- ✔ It 1 = the possibility that none of the people around you may be conscious
- ✔ It 2 = your conviction that there are minds in those bodies, sight behind those eyes, hearing in those ears, etc.
✔ To consider [the possibility that none of the people around you may be conscious] produces an uncanny feeling. On the one hand [the possibility that none of the people around you may be conscious] seems conceivable, and no evidence you could possibly have can rule [out] [the possibility that none of the people around you may be conscious] decisively. On the other hand [the possibility that none of the people around you may be conscious] is something you can't really believe is possible: [your conviction that there are minds in those bodies, sight behind those eyes, hearing in those ears, etc.], is instinctive. But if [the power of] [your conviction that there are minds in those bodies, sight behind those eyes, hearing in those ears, etc.] comes from instinct, is [your conviction that there are minds in those bodies, sight behind those eyes, hearing in those ears, etc.] really knowledge? Once you admit the possibility that the belief in other minds is mistaken, don't you need something more reliable to justify holding on to [your conviction that there are minds in those bodies, sight behind those eyes, hearing in those ears, etc.]?