1. Premise (p) is true.
2. I have a belief that (p) is true.
3. The truth of (p) is indubitable.
However, if what is true is one's thoughts and nothing more, and something else, if it exists, would consist of nothing more than thoughts, then why not say that it is unnecessary to prove that other things are true in the first place, since whatever condition of our thoughts makes them true belongs to us...!
Unless we impose artificial restrictions on the boundaries of thoughts, we are left with a picture in which qualified thoughts are as foreign as the primary bodies of others: a kind of mind-matter equality, or preferential pan-capablism.
This is because the relation of us to another person is more than a secondary relation: instead, it is a tertiary or greater relation: (1) I to a thought, (2) a thought to a thought, and (3) another's thought to another. Or, perhaps, (1) A thought to myself, (2) myself to another, and (3) another to another's thought. Whatever the case, what qualifies the thought may as well belong to someone else! And, I could be the thought of another person!
But the relation of one thought to another might take place within the same mind!
In this sense, we may have an idea of someone else, but this is the same as relating through some idea (that relativistic medium) to some objective factor, such as a person. If what we consist of is thought, there is nothing preventing us from relating directly to objects, because we are already unrelated from our own bodies. Thought may have no inherent relation to bodies, except what it observes. And so, the relation to one's own body is just the same as the relation to some other body! But, via the senses, if the senses are what is necessary for thought, then the relation to other bodies is as primary as thought itself! Because both (the thought and the other) occur on the boundary between the interior self and the senses. The implications are broad, including:
*Automatic, as-is verification of the physical world (qua object, e.g. thought exists qua object or qua whatever-it-is so long as it comes from the senses).
*An increased status for objective ideas, because they have the status of thoughts.
*An increased functionality of intellectualizations of objects, since these intellectualizations have the same status as objects.
*A question about the rationality of entity statuses.
*Improved entity status potential, with reduced default entity status.