Knowledge

Knowledge, is, on one common philosophical account, justified, and true belief. If you believe that ponderous bodies rotate around the planet Jupiter, and can justify that belief with convincing evidence based on astronomical observations—experience—and your observations are reproducible and invulnerable to alternative explanations, and ponderous bodies truly rotate around Jupiter, you can claim the knowledge that your belief expresses.

However, 'knowledge' is very often used in a looser way to refer to any form of truth or belief, a whole body of truth or a whole system of belief. For "knowledge" in this latter sense, see world view, ideology, and religion.

In a more restricted and philosophical sense, knowledge is the central topic of the philosophical subdiscipline of epistemology. A good place to begin with this topic is by explaining why most philosophers do distinguish between knowledge on one hand and both truth and belief on the other hand.

Firstly, knowledge is said to differ from truth for the simple reason that not all truths are known; in other words, there are undiscovered truths. Some people (including some philosophers) are apt to respond to this by asking, "What sort of thing is an undiscovered truth?" This is an ontological issue, however, and most of us will probably be satisfied if we simply give examples. For instance, the second law of thermodynamics was already true prior to its being discovered in the 19th century.

Secondly, knowledge is said to differ from belief because we believe many things when we do not really know them.

Scepticism

A fundamental debate among philosophers concerning knowledge is about whether having knowledge, in the of justified true, is possible. According to a philosophical theory known as "scepticism" it is not. Its adherents argue that we cannot know that our perceptions are not the product of manipulations of our brains by some unrecognized agent or agent-like factor. Because we cannot ever know that, we cannot know anything. Even if ponderous bodies truly rotate around the planet Jupiter, we cannot know that....

To know

The word 'knowledge' abstracts, nominalizes, and reifies the verb 'to know'. In other words, it generates a concept, noun, and thing out of a physiological process, the process one performs to know something, the activity involved in knowing. One approach to talking about knowledge, then: first talk about 'to know'. That may lead to some insight into the meaning of 'knowledge'. Analogous examples: exploring the meaning of 'to think' as an approach to understanding the concept 'thought', or 'to live', to answer the question 'what is 'life'.

Dictionaries do not help in describing the meaning of 'to know', or 'to know something', or the activity involved in 'knowing', inasmuch as they define 'know' in terms of more complex words, such as 'recognize', 'acknowledge', 'perceive', words that, when defined, ultimately require knowing what 'know' means in order to understand their meaning: I recognize someone because I know that someone. I acknowledge that you can run faster than I can because I know you can. I perceive something because I know that I see, hear, feel, or smell it. 'To know', or 'to know something', serves as an fundamental invariant for defining its numerous more complex synonyms and senses.

Where can we go then to learn what 'to know' means? Perhaps nowhere, and no need. We know the meaning of 'know' independently of linguistic definitional expressions because, during development, as we learned our natural language, the speakers in our environment used the word in real-world situations in ways that indicated its meaning: "I know, you're hungry"; "do you know your ABCs? Say them for me."; "Do you know where your brother went?"; "I know it hurts, but this will help make the pain go away".

One might respond, of course, we learn the meanings of many hundreds of words in that way, by the way our elders use them as we learn our native language, without the need of formal definitions. But according to some semanticists, the word 'know' has special properties that distinguishes it from most other words, indeed from all other words save for about 60 words that share the same special properties of 'know'. One of those properties is they are the only set of words characterized by being present in all the natural languages that have been studied, including languages from a wide spectrum of language families. Other words may find their equivalents in some other languages but not all other languages, or if they are so present in all other languages they are readily definable in terms of the basic set that contains the word 'know'. Another property, already alluded to, is that words in the set with 'know' cannot be defined in terms of simpler words, only in terms of words that are conceptually more complex.

Along with 'know', those 60 or so words provide a basic core of irreducibly simple words whose meanings, once grasped through sociocultural experience, remain intuitive, and serve as a base set of words for defining all other words without circularity. Given that their meanings are learned through usage, all words not in the set with 'know' can be defined in terms of the words in the set with 'know'.

Semanticists refer to those intuitively meaningful words as semantic primes, or semantic primitives. They include such basic words as 'I', 'you', 'someone', 'something', 'thing', 'hear', 'see', 'feel', 'want', 'know', 'one', 'two', 'many/much',....

[More to come....]

---