The method of the present work is mixed. It is partly historical, and partly logical. The historical portions exhibit the way in which words and inflections _have been_ used; the logical, the way in which they _ought to be_ used. Now I cannot conceal from either my readers or myself the fact that philological criticism at the present moment is of an essentially {xv} historical character. It has been by working the historical method that all the great results both in general and special scholarship have been arrived at; and it is on historical investigation that the whole _induction_ of modern philology rests. All beyond is _[`a] priori_ argument; and, according to many, _[`a] priori_ argument out of place. Now, this gives to the questions in philology, to questions concerning the phenomena of concord, government, &c. a subordinate character. It does so, however, improperly. Logic is in language what it is in reasoning,--a rule and standard. But in its application to reasoning and to language there is this difference. Whilst illogical reasoning, and illogical grammar are equally phenomena of the human mind, even as physical disease is a phenomenon of the human body, the illogical grammar can rectify itself by its mere continuance, propagation, and repetition. In this respect the phenomena of language stand apart from the other phenomena of either mind or organized matter. No amount of false argument can make a fallacy other than a fallacy. No amount of frequency can make physical disease other than a predisposing cause to physical disorganization. The argument that halts in its logic, is not on a _par_ with the argument that is sound. Such also is the case with any bodily organ. No prevalence of sickness can ever evolve health. Language, however, as long as it preserves the same amount of intelligibility is always language. Provided it serve as a medium, it does its proper work; {xvi} and as long as it does this, it is, as far as its application is concerned, faultless. Now there is a limit in logical regularity which language is perpetually overstepping; just as there is a logical limit which the reasoning of common life is perpetually overstepping, and just as there is a physiological limit which the average health of men and women may depart from. This limit is investigated by the historical method; which shows the amount of latitude in which language may indulge and yet maintain its great essential of intelligibility. Nay, more, it can show that it sometimes transgresses the limit in so remarkable a manner, as to induce writers to talk about the _corruption of a language_, or _the pathology of a language_, with the application of many similar metaphors. Yet it is very doubtful whether all languages, in all their stages, are not equally intelligible, and, consequently, equally what they ought to be, viz., mediums of intercourse between man and man; whilst, in respect to their growth, it is almost certain that so far from exhibiting