Some say the the spiritual world is everything that is not known to the five senses, or that it is everything that is not "physical", or everything that cannot be known by science.

I beg to differ.

I think the "place" that we perceive in these moments is a specific set of real stimuli that, certainly, do not impinge on our five senses, and are not "physical", but are not everything that is not these things.

I do think that the spirit world is amenable to certain very limited types of scientific inquiry - or else why would I be writing this? This inquiry is so limited, though.

Most science is really an extension of our physical senses, filtered through strict rules of mathematical logic and the well tested rules of the scientific method.

The spirit world is a problem on at least two of these fronts. It is not perceivable to our physical senses - at least not as we define the five that are so obvious - and so it cannot be observed more closely by a technique of extending the senses (like microscopy). It manages to elude the scientific method by virtue of its unrepeatability - whether due to our poor resolution in observing it or as a quality of its true nature.

I will not go so far as to say that mathematicians will never find certain kinds of reasoning that correspond to the nature of the spirit world because I suspect mathematics is the language in which the fundamental structure of the universe (and the spiritual world is certainly part of the universe!) is written. Of course such mathematics may 1. never be recognised as such due to the difficulty of developing a useful database of what is "out there" to compare it to and 2. may not be something we are capable of expressing, ever.

So what does that leave me? Well, I think it is still possible to form some necessarily vague generalisations about our accrued learning about this strange, shadowy "other world". This is aided and permitted by our species' many diverse and improving means of sharing ideas. Language, especially recorded laguage, and the arts - again, especially those that can be transported and shared - have done us the service, anecdotal though it may be, of developing a database for study.