I came across this video of Feynman today where he explains the difference between knowing the name of a thing and knowing something. It's a great point, and it goes all the way back to Galileo, 1632 (and presumably even earlier!). I referenced it in my MSc thesis:

"[There is] a conversation in the Dialogo between Salviati and Simplicio, who represent the Galilean and Aristotelian views respectively. When Simplicio is asked the cause by which heavy objects are conducted downwards he replies, “That is quite familiar, anyone knows that it is gravity.”   To which Salviati responds, “You are mistaken, Signor Simplicio, you ought to have said: anyone knows it is called gravity.” (Paraphrase from Dijksterhuis, 1961 p.338, who is quoting Galileo, Dialogo II)

This pithy exchange illustrates a very fundamental point: we cannot expand our knowledge simply by bestowing names.   This is not to say that there is no value in concepts and the naming of them. Thinking that there is something systematic about the way heavy objects fall to the earth was an excellent supposition. But its excellence derived from the power of this assumption to motivate physicists to uncover the nature of that systematic connection and to establish the degree to which the connection was autonomous. The mere declaration that a body falls to the earth because of ‘gravity’, with no effort made to specify the sense in which we are justified in ascribing a common cause to various cases of descent, has very little explanatory value."

It's a nice little concept, and Feynman explains it beautifully.