[Aquinasfan]

That's an interesting question. I have a nephew with schizophrenia. He has challenged me to prove his mind is malfunctioning. It's difficult to do this.

My point though, is that a materialist worldview makes it impossible in principle to know at any moment whether one can trust the the evidence of one's senses or one's thought at all. In reality, we can check the correspondence of our thought against the outside world, contradicting the above corollary of materialist philosophy.

[js1138]

In reality, we can check the correspondence of our thought against the outside world, contradicting the above corollary of materialist philosophy.

You can do that if you start by assuming that your brain is not malfunctioning. But what if it is?

The people whose brains we think are malfunctioning don't think they are.

[Doctor Stochastic]

How world a spiritualst world allow you to know that your senses are working? How do you distinguish the validity of voices telling to kill a few people (Andrea Yeats) or many people (Joan of Arc)?