But my subject is inexhaustible; it has no limits except those, which indeed may be often narrow enough, imposed by my own ignorance on the one side; and on the other, by the necessity of consulting your patience, and of only choosing such matter as will admit a popular setting forth. These necessities, however, bid me to pause, and suggest that I should not look round for other quarters from whence accessions of new words are derived. Doubtless I should not be long without finding many such. I must satisfy myself for the rest with a very brief consideration of the _motives_ which, as they have been, are still at work among us, inducing us to seek for these augmentations of our vocabulary. And first, the desire of greater clearness is a frequent motive and inducement to this. It has been well and truly said: “Every new term, expressing a fact or a difference not precisely or adequately expressed by any other word in the same language, is a new organ of thought for the mind that has learned it”{121}. The limits of their vocabulary are in fact for most men the limits of their knowledge; and in a great degree for us all. Of course I do not affirm that it is absolutely impossible to have our mental conceptions clearer and more distinct than our words; but it is very hard to have, and still harder to keep, them so. And therefore it is that men, conscious of this, so soon as ever they have learned to distinguish in their minds, are urged by an almost irresistible impulse to distinguish also in their words. They feel that nothing is made sure till this is done. {Sidenote: _Dissimilation of Words_} The sense that a word covers too large a space of meaning, is the frequent occasion of the introduction of another, which shall relieve it of a portion of this. Thus, there was a time when ‘witch’ was applied equally to male and female dealers in unlawful magical arts. Simon Magus, for example, and Elymas are both ‘witches’, in Wiclif’s _New Testament_ (Acts viii. 9; xiii. 8), and Posthumus in _Cymbeline_: but when the medieval Latin ‘sortiarius’ (not ‘sortitor’ as in Richardson), supplied another word, the French ‘sorcier’, and thus our English ‘sorcerer’ (originally the “caster of lots”), then ‘witch’ gradually was confined to the hag, or female practiser of these arts, while ‘sorcerer’ was applied to the male.