There are two ways to read this passage: we can take Crimsworth’s claims about Frances’ devoir at face value, and deduce his preferred model of prose style; or we can treat his claims with skepticism, and uncover what he ironically reveals about his attitude towards Frances.
Crimsworth’s criticism that “the style stood in great need of polish and sustained dignity” suggests that his model was the ‘Augustan prose’ of the 18th century, which reached its pinnacle in the essays of Samuel Johnson. Here, for example, is the first sentence of Johnson’s preface to the plays of Shakespeare:
That praises are without reason lavished on the dead, and that the honours due only to excellence are paid to antiquity, is a complaint likely to be always continued by those, who, being able to add nothing to truth, hope for eminence from the heresies of paradox; or those, who, being forced by disappointment upon consolatory expedients, are willing to hope from posterity what the present age refuses, and flatter themselves that the regard which is yet denied by envy, will be at last bestowed by time.
Samuel Johnson (1765). The Plays of William Shakespeare, vol. I, p. v.. London: printed for J. and R. Tonson, etc.
Johnson’s long sentences use parallel clauses for balance and antithesis; he repeats ideas in different words for emphasis or to make fine distinctions of meanings; and he employs Latinisms and abstractions. His style was enormously influential, both for and against: his fans admired his elegance and sublimity; while his detractors scorned his pomposity, obscurity, and monotony.
If we look at Frances’ devoir in this context, we can see that it lacks the balanced parallelisms and rational consideration of thesis and antithesis in complex grammatical structures, of Crimsworth’s prose models, substituting instead an outpouring of feeling in short clauses juxaposed without conjunctions.
Of course, even if we take Crimsworth’s observations at face value, we are not obliged to agree with him: we might well prefer the emotional force of Frances’ style. Virginia Woolf, for example, criticized Charlotte Brontë’s attempts to emulate the Johnsonian prose style:
The sentence that was current at the beginning of the nineteenth century ran something like this perhaps: “The grandeur of their works was an argument with them, not to stop short, but to proceed. They could have no higher excitement or satisfaction than in the exercise of their art and endless generations of truth and beauty. Success prompts to exertion; and habit facilitates success.” That is a man’s sentence; behind it one can see Johnson, Gibbon and the rest. It was a sentence that was unsuited for a woman’s use. Charlotte Brontë, with all her splendid gift for prose, stumbled and fell with that clumsy weapon in her hands.
Virginia Woolf (1929). A Room of One’s Own, p. 115. London: Hogarth Press.
The other approach to this passage is to take seriously the fact that Crimsworth is mistaken: the quoted passage from Frances’ devoir is not “mostly made up” of “short and somewhat rude sentences”. Such a mistake seems quite telling: it suggests in Crimsworth such a need to criticize his pupil’s work that he is driven to find faults that are not there. It is not hard to see that this arises from his patriarchal view that the relationship between man and woman corresponds to that between master and pupil. Here’s Helen Davis making this point:
Frances’s devoirs (which he places in quotes) and her quick mastery of English also serve to undermine Crimsworth’s narrative claims of awakening her through his own skills as teacher because they clearly demonstrate her intelligence, eloquence, and creativity. After quoting a devoir that is both eloquent and creative, he says that “It was mostly made up, as the above example shows, of short and somewhat rude sentences, and the style stood in great need of polish and sustained dignity”. […]
That the devoir is so obviously not composed of short, unpolished sentences, coupled with Frances’s first oral recitation, indicates that she has a natural aptitude for writing and speaking well in English. Crimsworth presents her as coming into beauty and intelligence after he meets her so that he can claim credit for her transformation and demonstrate control over her, but instead the implied reader sees his unreliability when discussing Frances. The contrast between her reality, and his description of that reality, also foregrounds her intelligence and determination to the implied reader.
Helen H. Davis (2015). ‘“I seemed to possess two wives”: Implied Narrative in Charlotte Brontë’s The Professor’. Journal of Narrative Theory 45:2, p. 202.
Crimsworth needs to find fault with Frances’ work in order to maintain the Victorian view of the husband as the teacher and superior of his wife, a view that Frances has to challenge in order to achieve a relationship of equals. While she considers his proposal of marriage, Crimsworth mediates on the role of husband:
There is something flattering to man’s strength, something consonant to his honourable pride, in the idea of becoming the providence of what he loves—feeding and clothing it, as God does the lilies of the field.
Charlotte Brontë (1857). The Professor, vol. 2, pp. 169–170. London: Smith, Elder & Co.
But Frances rejects the idea of giving up her work, and even though we can only see her through Crimsworth’s narrative, we can see that she is already considering how best to manage him so as to meet her needs without wounding his amour-propre:
“How rich you are, monsieur!” and then she stirred uneasy in my arms. “Three thousand francs!” she murmured, “While I get only twelve hundred!” She went on faster. “However, it must be so for the present; and, monsieur, were you not saying something about my giving up my place? Oh no! I shall hold it fast;” and her little fingers emphatically tightened on mine.
Brontë, pp. 170–171.