Knowledge is an abstract concept without any reference to the tangible

world. It is a very powerful concept, yet it has no clear definition so far.

From the Greek philosophers up to present experts in knowledge man-

agement, people tried to define knowledge but the results are still very

fuzzy. This chapter has the intention of showing the most significant as-

pects of the dispute over the definition of knowledge, and the main con-

ceptual barriers in that endeavor. In the first part of the chapter we dis-

cuss about the knowledge nature and the attempts made in epistemology

to define knowledge. The well-known definition that knowledge is justi-

fied true beliefis shown to have the limitations given by the justification

condition and the truth nature. In the second part, we consider the meta-

phorical approach to knowledge explanation and we present the main

metaphors used for knowledge in the managerial literature: knowledge as

objects, knowledge nuggets, knowledge as an iceberg, and knowledge as

stocks and flows. In the last part, we introduce a new paradigm of meta-

phorical thinking based on the knowledge energy. This metaphor opens

new opportunities for understanding knowledge as a multi-field paradigm

composed of the rational, emotional, and spiritual knowledge fields.