What makes people irrational thinkers?

[emjay]

If rational just means 'reasoned' then people can reason themselves into all sorts of positions, using all sorts of different 'frameworks' of understanding to get there. So no, I don't think you're irrational... or any more irrational than anyone else, myself included... you just use a different framework of understanding than many people, ie Aristotle etc, to arrive at your conclusions. And can a rational person not be a physicalist? Again I don't see why not, if all we mean is 'reasoned' then you only need to look at all the different theories on consciousness for example, and/or solipsism etc, to see the diverse places reason can take people. It's always been kind of ironic to me how we can all claim to be using logic, but yet never agree on anything, and this is the main reason why I think... just different frameworks of understanding. Anyway, as to the book/Hart, I'm not reading it, just following the discussion here, so no comment from me on that.

Exactly. Logic *alone* is a very, very weak filter for ideas. At best, it determines if they are internally consistent. It cannot determine if they are actually true.

This is also true of math, by the way.

At some point, it is crucial to have actual observations as an additional filter. Logic and math alone simply are not enough.

Is what you're saying basically the difference between inductive and deductive reasoning? Ie the latter has the conclusion fully contained in the premises, and in a sense through it you're learning nothing new on account of that, but the former makes testable hypotheses/generalisations from observations. Top down vs bottom up logic, where the latter is where it actually gets tied to reality, through those testable hypotheses?

Now, the question is whether the *completely logically defensible* position of solipsism is 'rational'. I would say not, but that is because of my metaphysical biases, I guess.

I was mainly thinking about people like @bennyboy... I don't know if he's still around... I haven't seen him in a long time. We used to have some interesting conversations about consciousness, but our perspectives couldn't be much more radically opposed. His was along the lines of solipsism I think, or had elements of it, but I wouldn't say for a second that he wasn't rational or that his theories weren't arrived at rationally... just from a different, and more inward focused, perspective.