Epistemology is a perennial subject. Only when human knowledge ceases to grow can reflection on the nature of this knowledge come to an end. We must perpetually restate the problems of knowledge and constantly redefine the concept of knowledge in order to elucidate an everchanging knowledge-situation, and in order to draw conclusions from new departures in human knowledge. Changes in epistemology thus follow like a shadow (but not in any direct or functional way) changes in human knowledge. New and significant departures in human knowledge invariably cause a shift of the epistemological lenses. The development of semantics in the 20th century was an occasion for one of these shifts. The new epistemological vision resulting from this shift has been known as the 'semantic" concept of knowledge. This concept of knowledge attempts to establish the primacy of linguistics over epistemology, the primacy of the criteria of meaning over epistemological criteria; it claims that only by establishing clear criteria of meaning can we delineate the realm of significant knowledge.