[bluetomcat]

You have to start with an attempt to define knowledge. It is rooted in observation and experience, and has the ability to invalidate itself in the face of new observations and experiences. In that sense, it is transient and ephemeral in the temporal domain. You can try to derive laws and models which have practical utility here and now, but those laws will always erode with the passing of time.

[ricardo_nh]

yes of course, I agree. but you don't need to define knowledge for that. all you have to do is see the cases where knowledge is attributed to subjects and what are the requisites for that in each context. if we are talking about scientific knowledge, yes I agree with your definition. but there are other types of knowledge. And my point was that to be a "know it all" it has more to do with one's approach to things, to a constant epistemic approach, than having an actual list of things one knows. A "know it all" is not an expert, but someone who looks for what is to be known in every situation of life