Published online by Cambridge University Press: 03 May 2011
In An Essay Concerning Human Understanding (1690), John Locke describes an encounter with a group of physicians immersed in learned debate about liquor in the nerves, a debate which captures the importance of definitions in medicine:
the Debate having been managed … by variety of Arguments on both sides, I (who had been used to suspect, that the greatest part of Disputes were more about the signification of Words than a real difference in the Conception of Things) desired … they would first examine … what the Word Liquor signified … upon Examination found, that the signification of that Word was not so settled and certain, as they had all imagined; but that each of them made it a sign of a different complex Idea. This made them perceive, that the Main of their Dispute was about the signification of that Term; and that they differed very little in their Opinions, concerning some fluid and subtile Matter, passing through the Conduits of the Nerves; though it was not so easie to agree, whether it was to be called Liquor(Locke 1997 iii, ix, 16)
The ‘examination’ of the meaning of ‘liquor’ by these seventeenth-century physicians probably involved further discussion, rather than reference to dictionaries, which were available, but far from ubiquitous – and many would not have been helpful with a word as common as ‘liquor’.