One of the primary channels between your shifting, ever-changing and elusive thought-world and the more fixed, slower-moving and fairly solid physical world is the thing called a word. Writing and thinking; thinking and writing: the only real difference between the two is that writing attempts to encapsulate thought using the established mechanism of words.
What is a word? There have been hundreds of textbooks of a very advanced and intricate nature written on the subject - using words themselves of course - but let’s keep it as simple as we can:
A word is an attempt to capture a thought.
Defined by the dictionary as ‘single distinct meaningful element of speech or writing’, amongst the many things invented by humanity it must be said that the word is one of the most successful, as the mere fact that you are reading this sentence demonstrates. Unable to convey meaning in any other way directly to you, these words have captured certain thoughts which you are decoding even as you read them.
Words are a channel, then, a code, an ever-changing, ever-growing set of reference points or ‘attempts to capture thoughts’, which we broadly share in common in order to achieve certain kinds of communication. Certainly there are other means of communicating, non-verbal and non-written, upon which a great amount of human discourse depends - but only the word can be so precise and intellectually satisfying; only words offer a kind of permanence.
Words are the means, perhaps the primary means, by which that continually moving, changing, fleeting, internal world can gain some kind of longevity, some kind of recognition or acknowledgement. Without words, your inner world would remain largely unknown and unexplored, even by you. As humans invented language, it could be said, so they invented or discovered or defined themselves.
Ursula Le Guin, renowned American author, once said: ‘Poetry and fiction use words in somewhat different ways, but they are both attempting to say various things that probably cannot be said at all. Or you could put it this way: Art doesn't tell “the truth”, it makes truth.’