It has not been the author's design to notice _all_ the synonyms in the language--that, as he remarks, would be an almost endless undertaking; 'but merely, after excluding technical terms, and words which do exactly coincide, to select a few of those groups of words which are in most frequent use, and are most liable to be confounded.' His purpose, perhaps, will be more distinctly shewn, if we add a few more sentences from the preface. 'Many persons,' says he, 'imagine that two words must either coincide precisely in their meaning, so as to be, in the primary and strict sense of the word, "synonymous," or else stand for two (more or less) distinct _things_. Indeed, it would often be regarded as almost a truism to assert this; but those who maintain such an opinion overlook the fact, that two words, without exactly coinciding in sense, may nevertheless relate to one and the same thing, regarded in _two different points of view_. An illustration of this is afforded in the relation which exists between the words, "inference" and "proof." Whoever justly infers, proves; and whoever proves, infers; but the word "inference" leads the mind from the premises which have been assumed, to the conclusion which follows from them; while the word "proof" follows a reverse process, and leads the mind from the conclusion to the premises. We say: "What do you infer _from_ this?" and "How do you _prove_ that?"[5] Another illustration may be quoted in the synonyms, "expense" and "cost." The same article may be expensive and costly; but we speak of _expense_ in reference to the means of the purchaser; of _cost_, in reference to the actual value of the article.' This work does not profess to deal much with _etymologies_; the author thinking that any very strict attention to the _derivation_ of words, in connection with synonyms, would only tend to confuse the subject. The history of the origin and growth of words must undoubtedly throw light upon their meanings; but he, nevertheless, holds the two questions to be completely distinct and separable; and thinks that, in an inquiry into the _actual_ and _present_ meaning of a word, the consideration of what it originally meant may frequently lead us into error. A few suggestive remarks are given upon this matter. 'Our question is, not what _ought_ to be, or formerly was, the meaning of a word, but what it _now_ is; nor can we be completely guided by quotations from Shakspeare or Milton, or even from Addison or Johnson. Language has undergone such changes, even within the last sixty or seventy years, that many words, at that time considered pure, are now obsolete; while others--of which the word "mob" is a specimen--formerly slang, are now used by our best writers, and received, like pardoned outlaws, into the body of respectable citizens.' The standard, accordingly, to which the author refers in the work before us, is the sense in which a word is used by the purest writers and most correct speakers of our own days.