Within the scope of the problem of demarcation there seems to be an implicit distinction between pseudoscience and non-science. Trying to make explicit what such distinction might be, I wonder: Does the difference between pseudoscience and non-science amount simply to the fact that the former "pretends to be scientific" whereas the latter does not? --- What does it really mean for some theory "to pretend to be scientific"? (And, could it be that theories we might consider pseudoscientific at present time, would turn in future into scientific ones (just as it happens from time to time with non-scientific theories that evolve into scientific ones?))
I think that pseudoscience is a field that makes scientific claims but is not science, thus giving off the impression that it is scientific. I think it's important to not make it something the practitioner does (such as "pretends to be science") because even if someone stands up an repetitively says "I'm not doing science" that shouldn't change our perception of his field, and I do think that pseudoscience is a description of a kind of field of knowledge.