Knowledge of Acquintance and Knowledgea About

In a passage from his book Psychology, William James proposed the idea of knowledge of acquaintance and knowledge about. As he wrote to open the passage “there are two kinds of knowledge, broadly and practically distinguishable: we may call them respectively knowledge of acquaintance and knowledge-about.” James’s meaning of knowledge of acquaintance, in contrast to the knowledge about, could be interpreted as the knowledge for which one cannot convey, thought, meaning, and/or ideas, with language.
As James stated early on in his passage, “I am acquainted with many people and things, which I know very little about, except their presence in the places where I have met them.” He then went on and told us:
I know the color blue when I see it, and the flavor of a pear when I taste it! I know an inch when I move my finger through it; a second of time, when I feel it pass; an effort of attention when I make it; a difference between two things when I notice it; but about the inner nature of these facts or what makes then what they are, I can say nothing at all.

So I believe that in saying all this, James means that although he knows these things, he lacks the language to convey to other any of the elemental facts about them; thus, James tells us he cannot impart acquaintance, describe, tell, and/or define any of them to anyone who hasn’t already experienced it himself. All he can tell people is this is a blue color, or there is a unique taste of pear, or etc. He can state the fact of them but can’t tell us “about the inner natures” of them. That is, from the above examples, I believe that James was relating knowledge of acquaintance with by way of the elemental experiences of the five senses of humans, or maybe it can be referred what is called the “common sense.” Further on in the passage, James stated “In minds able to speak at all there is, it is true, some knowledge about everything.” Just as James pointed out, we all know something about everything, even if