No reason justifies disbelief.

[bennyboy]

I wouldn't know, Camus and I are are having a discussion about it, but there's nothing preventing a person from using the method on their intuitions, and intuition may be based on empirical observation, itself.  What we have been able to agree on, at least I think...is that even if intuition were distinct from empirical observation and capable of being a basis for knowledge...that just like empirical observation...it is in itself suspect on well established grounds and requiring some method of winnowing down false hits.

A science of mind might be a very personal thing, and there have in fact been schools of psychology based on introspection. However, science as we normally mean today it does not include personal insight.

Case in point, we have done scientific research on buddhist (and broadly) meditations claims, as well as a whole range of alleged insights and intuitions.  Their consistent dual failure to produce results or establish themselves as other than empirical is why both sets of claims have been abandoned by all but the most credulous researchers.  Don't get me wrong, more power to the folks who keep beating their heads against that wall.  They could always discover something tomorrow, just like the sun may not rise tomorrow.

The Buddhists know the territory of mind particularly well, and I'd point to the Tibetan tradition of meditation as the best case in point. Now, you might not agree with their source attributions, but they know truths about what this or that state of mind is like and how to achieve it unlike anyone, including scientists.

Even if you don't agree that this is true, there is a whole category of questions which science cannot answer-- those about qualia.
What is it like to taste chocolate?
What is it like to watch the sun rise after sleeping on a park bench in the middle of winter?
What is it like not to have the answer to a question, and then have the answer enter into your awareness, fully-formed?

Science can talk around these questions, but cannot answer them. Knowledge of what things are like is in the experience of them, not in descriptions of brain function about them.