Knowledge is the awareness and understanding of truths, facts, or information gained through experience or learning (a posteriori) or through introspection (a priori). Knowledge is the self-awareness of possessing interrelated information that, taken individually, has less value and utility.
“Knowledge” is a term that can have different meanings depending on the context, but it is somehow related to the concepts of meaning, information, instruction, communication, representation, learning, and mental stimulation.
Knowledge is different from mere information. Both are nourished by true statements, but knowledge is a particular form of knowledge, endowed with its own utility. While information can exist independently of who can use it, and thus can be somehow preserved on some kind of medium (paper, computer, etc.), knowledge exists only insofar as there is a mind capable of possessing it. In fact, when one claims to have explicated knowledge, one is actually preserving the information that makes it up, along with the correlations between them, but true knowledge exists only in the presence of a user who relates that information back to his or her own personal experience. Basically, knowledge only exists when an intelligence can use it.
In philosophy, knowledge is often described as information associated with intentionality. The study of knowledge in philosophy is entrusted to epistemology (which is concerned with knowledge as experience or science and is thus oriented toward the methods and conditions of knowledge) and gnoseology (which is found in the classical philosophical tradition and is concerned with the a priori problems of knowledge in a universal sense).
In philosophy, the concept of knowledge is sometimes used to denote the act of the subject as an explication of its typical virtuality vis-à-vis the object, or again the object itself as known, i.e. the cognitive content (in the latter sense the term is usually used in the plural). Fundamental is the distinction, which is already present in semantic usage in almost all languages, but is explicitly found at the philosophical level, between a kind of direct knowledge, where to know means to “come into contact” with a thing, to have a “vision or living experience” of it, and a kind of indirect direct knowledge, where to know means to have notions or information “about” a thing, to “know” something about it, but without having direct experience of it: for example, a blind person may have certain “information” or notions about light, without ever having directly experienced it. However, this distinction cannot be reduced to that between sensible and rational knowledge, since this would presuppose that the only direct knowledge is sensible knowledge: indeed, intuition of logical principles or mystical experience (however questionable) stand as direct knowledge without being able to qualify as sensible knowledge. The evaluation of these two kinds of knowledge and their relations, like the relation between subject and object in general, is the subject of a special philosophical discipline: gnoseology or the theory of knowledge.
From the point of view of knowledge, sociology itself requires the study of the relationship over time between intellectual life and the dynamics of political, cultural, and religious forces at work in the social contexts under observation. The existence of a link between society and forms of knowledge (philosophies, ideologies, cultural patterns) was already present in G. B. Vico’s Scienza nuova (1725). K. Marx develops the idea by considering knowledge as a product of the dominant productive structure and social system. Hence his radical critique of ideology as false consciousness. However, it is only with K. Mannheim that the sociology of knowledge acquires its own thematic and methodological autonomy. The analysis of the intellectual class, which is called upon to “represent” and mediate conflicting social interests in society, becomes central. Hence a critique of ideology as radical as Marx’s, but completely detached from its social connotation. P.A. Sorokin also sought to link social change to the evolution of mentalities outside a rigid class paradigm. The later strand of analysis, however, focuses on the production of knowledge related to everyday life in the context of highly technologically developed societies (P. L. Berger, T. Luckmann, Reality as Social Construction). For these authors, the possibility of critical knowledge is linked to the privileged observation of language and behavior.