  Concepts were said to signify naturally, and to have the same signification for all thinkers, or at least all thinkers with the same experience, but spoken terms, and the written terms which were subordinated to them, were thought to acquire their signification by some original act of imposition. While most authors were careful not to commit themselves to any account of how this original imposition actually occurs, and while it was recognized that words such as ‘person’ and ‘spirit’ (both important in theological contexts) do acquire new connotations, it was generally supposed that the signification of common nouns within a given conventional language remains stable. Proper names were both easier and more difficult to account for. They were more difficult because it is not entirely plausible to account for the stability of their signification by appeal to standard definitions. They were easier because there are easily ascertainable instances of original imposition, particularly through Christian baptism, though Paul of Venice explicitly recognized that non-Christians have equivalent name-giving ceremonies. 