The Tradëscan Codex

The hardest part is figuring out how we have the thoughts in the first place! There's a certain amount of evidence as to the cognitive relationship between words and concepts(eg from aphasic patients who have coherent thoughts they want to express but constantly retrieve the wrong word from their mental lexicon - as you can imagine, it's enormously frustrating to want to say "Pass the salt" and to come out with "Bugger the fruit juice") and which areas of the brain are responsible for which parts of the process (damage in some areas makes people speak grammatically fluently but what they say is nonsense, damage to other areas buggers up the syntax but at least the individual words are correct). If you're interested at all in an empirical rather than a philosophical approach to language and the mind, I can't recommend Stephen Pinker's The Language Instinct highly enough. It's totally accessible to the lay person, really well written and entertaining, very thought-provoking, and the science is spot on.