Of this, Dr. Fitzedward Hall remarks, in his "Recent Exemplifications of False Philology": "That any one but Cobbett would abide this as English is highly improbable; and how the expression—a quite classical one—which he discards can be justified grammatically, except by calling its than a preposition, others may resolve at their leisure and pleasure."
Thanks. There are many persons who think it in questionable taste to use thanks for thank you.
That. The best writers often appear to grope after a separate employment for the several relatives.
"'That' is the proper restrictive, explicative, limiting, or defining relative.
"'That,' the neuter of the definite article, was early in use as a neuter relative. All the other oldest relatives gradually dropt away, and 'that' came to be applied also to plural antecedents, and to masculines and feminines. When 'as,' 'which,' and 'who' came forward to share the work of 'that,' there seems to have arisen not a little uncertainty about the relatives, and we find curious double forms: 'whom that,' 'which that,' 'which as,' etc. Gower has, 'Venus whose priest that I am'; Chaucer writes—'This Abbot which that was an holy man,' 'his love the which that he oweth.' By the Elizabethan period, these double forms have disappeared, and all the relatives are used singly without hesitation. From then till now, 'that' has been struggling with 'who' and 'which' to regain superior favor, with varying success. 'Who' is used for persons, 'which' for things, in both numbers; so is 'that'; and the only opportunity of a special application of 'that' lies in the important distinction between coördination and restriction. Now, as 'who' and 'which' are most commonly preferred for coördination, it would be a clear gain to confine them to this sense, and to reserve 'that' for the restrictive application alone. This arrangement, then, would fall in with the most general use of 'that,' especially beyond the limits of formal composition.
"The use of 'that' solely as restrictive, with 'who' and 'which' solely as coördinating, also avoids ambiguities that often attend the indiscriminate use of 'who' and 'which' for coördinate and for restrictive clauses. Thus, when we say, 'his conduct surprised his English friends, who had not known him long,' we may mean either that his English friends generally were surprised (the relative being, in that case, coördinating), or that only a portion of them—namely, the particular portion that had not known him long—were surprised. In this last case the relative is meant to define or explain the antecedent, and the doubt would be removed by writing thus: 'his English friends that had not known him long.' So in the following sentence there is a similar ambiguity in the use of 'which': 'the next winter which you will spend in town will give you opportunities of making a more prudent choice.' This may mean, either 'you will spend next winter in town' ('which' being coördinating), or 'the next of the winters when you are to live in town,' let that come when it may. In the former case, 'which' is the proper relative; in the latter case, the meaning is restrictive or defining, and would be best brought out by 'that': 'the next winter that you will spend in town.'
"A further consideration in favor of employing 'that' for explicative clauses is the unpleasant effect arising from the too frequent repetition of 'who' and 'which.' Grammarians often recommend 'that' as a means of varying the style; but this end ought to be sought in subservience to the still greater end of perspicuity.
"The following examples will serve further to illustrate the distinction between that, on the one hand, and who and which, on the other:
"'In general, Mr. Burchell was fondest of the company of children, whom he used to call harmless little men.' 'Whom' is here idiomatically used, being the equivalent of 'and them he used to call,' etc.
"'Bacon at last, a mighty man, arose,
Whom a wise king and nation chose
Lord Chancellor of both their laws.'