THE SHERMAN PRINCIPLE IN RHETORIC.
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found in the average number of words used by any given author per sentence would also hold in regard to the number of finite verbs, or predications, found in each sentence. The results obtained convinced me also that there was a uniformity in the number of simple sentences per hundred of a given author." Mr. Gerwig expresses his conviction that the average number of predications and simple sentences in five hundred periods of any author who has achieved a style is approximately the average of his whole work. In particular he found that 'while Chaucer and Spenser put habitually over five main verbs in each sentence they wrote, and less than ten simple sentences in each hundred, Macaulay and Emerson used only a little over two verbs per sentence, and left over thirty-five verbs in each hundred simple.'
The theory which has grown out of these investigations has been most tersely stated by Mr. Hildreth, another student of Professor Sherman, who at the same time applies the theory to the Bacon-Shakespeare controversy. We read:
Ten years or more ago Professor Sherman, while investigating the course of stylistic evolution in English prose, made the discovery that authors indicate their individuality by constant sentence proportions, personal and peculiar to themselves. This was demonstrated especially with the number of words used per sentence in large averagings. It was found that De Quincey, Channing and Macaulay, if five hundred periods or more were taken, evinced this average invariably, and in the earliest as well as in the latest period of their authorship. This discovery led to the suspicion that good writers would be found constant in predication averages, in per cent, of simple sentences, and other stylistic details. Acting upon a suggestion to this effect, Mr. G. W. Gerwig, then a pupil of Professor Sherman, undertook an investigation that established the constancy of predication, as well as simple-sentence frequency, in given authors. . . . Professor Sherman and Mr. Gerwig have thus established by an examination of a great many authors, that writers are structurally consistent with themselves; that they possess a certain sentence-sense peculiarly their own. These investigators have established that by this instinct authors use a constant average sentence-length, and a certain number of predications per sentence, and that a given per cent, of their sentences will be simple sentences. . . . The work of these investigators covers a large amount of material and a wide field of literature. They have examined and compared the works of ancient and recent authors, early and late writings of the same author, and writings of the same author of different character, such as history and dialogue, poetry and prose.
[1] The results thus far obtained are sufficient to show that it is not possible for a writer to escape from his stylistic peculiarities.
The principle once established, its application to cases of disputed authorship is very plain. If each author employs but one set of average sentence proportions such as sentence-length, predication average and simple sentence frequency, it is only necessary to determine these constants for a disputed work and compare them with those of its supposed author. If the two sets of constants manifest a striking differ-
- ↑ This Professor Sherman tells me is an oversight. Neither he nor Mr. Gerwig think that the principle in question applies to poetry.