Knowing how we know is a fundamentally circular problem when it is described in human language. And knowing something about what is adds another circle, if the knowing being must itself be one of those things that exists.

These circular definitions and inferences need not be vicious circles. They may simply be a coherent set of ideas that we use to describe ourselves and the external world. If the descriptions are logically valid, or verifiable empirically, we think we are approaching the "truth" about things and acquiring knowledge.

How then do we describe the knowledge itself - as an existing thing in our existent minds and in the existing external world. Information philosophy does it by basing everything on the abstract but quantitative notion of information.

Information is stored or encoded in structures. Structures in the world build themselves, following natural laws, including physical and biological laws. Structures in the mind are partly built by biological processes and partly built by human intelligence, which is free, creative, and unpredictable.

Knowledge is information created and stored in minds and in human artifacts like stories, books, and internetworked computers.

Knowledge is actionable information that forms the basis for thoughts, actions, and beliefs.

Knowledge includes all the cultural information created by human societies. It also includes the theories and experiments of scientists, who collaborate to establish our knowledge of the external world. Scientific knowledge comes the closest of any knowledge to being independent of any human mind, though still dependent on an open interdependent community of inquirers.

To the extent of the correspondence, the isomorphism, the one-to-one mapping, between information structures (and processes) in the world and representative structures and functions in the mind, information philosophy claims that we have quantifiable personal or subjective knowledge of the world.

To the extent of the agreement (again a correspondence or isomorphism) between information in the minds of an open community of inquirers seeking the best explanations for phenomena, information philosophy further claims that we have quantifiable inter-subjective knowledge of other minds and of an external world. This is as close as we come to "objective" knowledge, and knowledge of objects - to Kant's "things in themselves."

Knowledge has historically been identified by philosophers with language, logic, and human beliefs. Epistemologists, from Plato's Theatetus and Aristotle's Posterior Analytics to modern language philosophers, identify knowledge with statements or propositions that can be logically analyzed and validated.

Specifically, traditional epistemology defines knowledge as "justified true belief." Subjective beliefs are usually stated in terms of propositions. For example,

S knows that P if and only if

(i) S believes that P,
(ii) P is true, and
(iii) S is justified in believing that P.

In the long history of the problem of knowledge, all three of these knowledge or belief "conditions" have proved very difficult for epistemologists. Among the reasons...

(i) A belief is an internal mental state beyond the full comprehension of expert external observers. Even the subject herself has limited immediate access to all she knows or believes. On deeper reflection, or consulting external sources of knowledge, she might "change her mind."

(ii) The truth about any fact in the world is vulnerable to skeptical or sophistical attack. The concept of truth should be limited to uses within logical and mathematical systems of thought. Real world "truths" are always fallible and revisable in the light of new knowledge.

(iii) The notion of justification of a belief by providing reasons is vague, circular or an infinite regress. What reasons can be given that themselves do not have just reasons? In view of (i) and (ii) what value is there in a "justification" that is fallible, or worse false?

(iv) Epistemologists have primarily studied personal or subjective beliefs. Fearful of competition from empirical science and its method for establishing knowledge, they emphasize that justification must be based on reasons internally accessible to the subject. Some mis-describe as "external" a subject's unconscious beliefs or beliefs unavailable to immediate memory. These are merely inaccessible, perhaps only temporarily.

(v) The emphasis on logic has led some epistemologists to claim that knowledge is closed under (strict or material) implication. This assumes that the process of ordinary knowing is informed by logic, in particular that

(Closure) If S knows that P, and P implies Q, then S knows that Q.

We can only say that S is in a position to deduce Q, if she is trained in logic.

It is no surprise that epistemologists have failed in every effort to put knowledge on a sound basis, let alone establish knowledge with apodeictic certainty, as Plato and Aristotle expected and René Descartes thought he had established beyond any reasonable doubt.

Perhaps overreacting to the threat from science as a demonstrably more successful method for establishing knowledge, epistemologists have hoped to differentiate and preserve their own philosophical approach. Some have held on to the goal of logical positivism (e.g., Russell, early Wittgenstein, and the Vienna Circle) that philosophical analysis would provide an a priori normative ground for merely empirical scientific knowledge.

Logical positivist arguments for the non-inferential self-validation of logical atomic perceptions like "red, here, now" have perhap misled some epistemologists to think that personal perceptions can directly justify some "foundationalist" beliefs.

The philosophical method of linguistic analysis (inspired by the later Wittgenstein) has not achieved much more. It is unlikely that knowledge of any kind reduces simply to the careful conceptual analysis of sentences, statements, and propositions.

Information philosophy looks deeper than the surface ambiguities of language.

Information philosophy distinguishes at least three kinds of knowledge, each requiring its own special epistemological analysis:

• Subjective or personal knowledge, including introspection and intuition, as well as communications with and perceptions of other persons and the external world.
• Communal or social knowledge of cultural creations, including fiction, myths, conventions, laws, history, etc.
• Knowledge of a mind-independent physical external world.

These quantum level processes are susceptible to noise. Information stored may have errors. When information is retrieved, it is again susceptible to noise, This may garble the information content. In information science, noise is generally the enemy of information. But some noise is the friend of freedom, since it is the source of novelty, of creativity and invention, and of variation in the biological gene pool.

Biological systems have maintained and increased their invariant information content over billions of generations. Humans increase our knowledge of the external world, despite logical, mathematical, and physical uncertainty. Both do it in the face of random noise, bringing order (or cosmos) out of chaos. Both do it with sophisticated error detection and correction schemes that limit the effects of chance. The scheme we use to correct human knowledge is science, a combination of freely invented theories and adequately determined experiments.