Here, also, 'whom' is equal to 'and him.'
"In the following instance the relative is restrictive or defining, and 'that' would be preferable: 'the conclusion of the "Iliad" is like the exit of a great man out of company whom he has entertained magnificently.' Compare another of Addison's sentences: 'a man of polite imagination is let into a great many pleasures that the vulgar are not capable of receiving.'
"Both relatives are introduced discriminatingly in this passage:—'She had learned that from Mrs. Wood, who had heard it from her husband, who had heard it at the public-house from the landlord, who had been let into the secret by the boy that carried the beer to some of the prisoners.'
"The following sentences are ambiguous under the modern system of using 'who' for both purposes:—'I met the boatman who took me across the ferry.' If 'who' is the proper relative here, the meaning is, 'I met the boatman, and he took me across,' it being supposed that the boatman is known and definite. But if there be several boatmen, and I wish to indicate one in particular by the circumstance that he had taken me across the ferry, I should use 'that.' 'The youngest boy who has learned to dance is James.' This means either 'the youngest boy is James, and he has learned to dance,' or, 'of the boys, the youngest that has learned to dance is James.' This last sense is restrictive, and 'that' should be used.
"Turning now to 'which,' we may have a series of parallel examples. 'The court, which gives currency to manners, should be exemplary': here the meaning is 'the court should be exemplary, for the court gives currency to manners.' 'Which' is the idiomatic relative in this case. 'The cat, which you despise so much, is a very useful animal.' The relative here also is coördinating, and not restrictive. If it were intended to point out one individual cat specially despised by the person addressed, 'that' would convey the sense. 'A theory which does not tend to the improvement of practice is utterly unworthy of regard.' The meaning is restrictive; 'a theory that does not tend.' The following sentence is one of many from Goldsmith that give 'that' instead of 'which':—'Age, that lessens the enjoyment of life, increases our desire of living.' Thackeray also was fond of this usage. But it is not very common.
"'Their faith tended to make them improvident; but a wise instinct taught them that if there was one thing which ought not to be left to fate, or to the precepts of a deceased prophet, it was the artillery'; a case where 'that' is the proper relative.
"'All words, which are signs of complex ideas, furnish matter of mistake.' This gives an erroneous impression, and should be 'all words that are signs of complex ideas.'
"'In all cases of prescription, the universal practice of judges is to direct juries by analogy to the Statute of Limitations, to decide against incorporeal rights which have for many years been relinquished': say instead, 'incorporeal rights that have for many years,' and the sense is clear.
"It is necessary for the proper understanding of 'which' to advert to its peculiar function of referring to a whole clause as the antecedent: 'William ran along the top of the wall, which alarmed his mother very much.' The antecedent is obviously not the noun 'wall,' but the fact expressed by the entire clause—'William ran,' etc. 'He by no means wants sense, which only serves to aggravate his former folly'; namely, (not 'sense,' but) the circumstance 'that he does not want sense.' 'He is neither over-exalted by prosperity, nor too much depressed by misfortune; which you must allow marks a great mind.' 'We have done many things which we ought not to have done,' might mean 'we ought not to have done many things'; that is, 'we ought to have done few things.' 'That' would give the exact sense intended: 'we have done many things that we ought not to have done.' 'He began to look after his affairs himself, which was the way to make them prosper.'
"We must next allude to the cases where the relative is governed by a preposition. We can use a preposition before 'who' and 'which,' but when the relative is 'that,' the preposition must be thrown to the end of the clause. Owing to an imperfect appreciation of the genius of our language, offense was taken at this usage by some of our leading writers at the beginning of last century, and to this circumstance we must refer the disuse of 'that' as the relative of restriction.[38]