There are no a priori obstacles to the scientific knowledge of the mind, but the scientific knowledge of the mind is not all the knowledge of the mind that there is. This is not an objection to science, it is just a distinction between different kinds of knowledge.

We have no proper understanding of the relationship between conscious thought and conscious sensation. The various forms of thought and sensation are underpinned by very different neural mechanisms; so how can the neural correlate of their conscious natures be the same? I don't think we are yet in a position to make such speculations. To make progress, we have to have a good conception of the phenomenology of consciousness, among other things.

One philosophically fascinating aspect of Catholicism is the very strange conception of reality it presents (the incarnation, the eucharist, judgement day etc.).

The wine itself has aesthetic value; but what it is for a wine to have aesthetic value cannot be understood without making reference to the experience to tasting it

I have a general moral: great philosophers may be great, but that is not a reason to follow them. Don't be a follower. Work it out for yourself.

I do think it's important to distinguish between intentionalism about consciousness and externalism about consciousness. Intentionalism says that consciousness is a form of intentionality - the representation of things to the mind. Externalism says that these things have to exist in order for them to be represented, or presented. These are different views.

If I was going to sum up my approach to this whole mind issue, I would say this: the question is often formulated in a very bad way - for example, by posing the question in terms of stuff. It's better to start with the things we do know: for example, that there are people and other thinking creatures, who have mental capacities. Our next step should be to say something about these capacities.