This movement between alternative linguistic modes conceived as alternative descriptive protocols is, I would argue, a distinguishing feature of all the great classics of the ‘literature of fact.
What is at issue here is not: What are the facts? but rather: How are the facts to be described in order to sanction one mode of explaining them rather than another? Some historians will insist that history cannot become a science until it finds the technical terminology adequate to the correct characterization of its objects of study, in the way that physics did in the calculus and chemistry did in the periodic tables. Such is the recommendation of Marxists, Positivists, Cliometricians, and so on. Others will continue to insist that the integrity of historiography depends on its use of ordinary language, its avoidance of jargon. These latter suppose that ordinary language is a safeguard against ideological deformations of the ‘facts.’ What they fail to recognize is that ordinary language itself has its own forms of terminological determinism, represented by the figures of speech without which discourse itself is impossible.
Like Kant before him, Darwin insists that the source of all error is semblance. Analogy, he says again and again, is always a ‘deceitful guide’ (see pp. 61, 66, 473). As against analogy, or as I would say merely metaphorical characterizations of the facts, Darwin wishes to make a case for the existence of real ‘affinities’ genealogically construed. The establishment of these affinities will permit him to postulate the linkage of all living things to all others by the ‘laws’ or ‘principles’ of genealogical descent, variation, and natural selection. These laws and principles are the formal elements in his mechanistic explanation of why creatures are arranged in families in a time series. But this explanation could not be offered as long as the data remained encoded in the linguistic modes of either metaphor or synecdoche, the modes of qualitative connection. As long as creatures are classified in terms of either semblance or essential unity, the realm of organic things must remain either a chaos of arbitrarily affirmed connectedness or a hierarchy of higher and lower forms. Science as Darwin understood it, however, cannot deal in the categories of the ‘higher’ and ‘lower’ any more than it can deal in the categories of the ‘normal’ and ‘monstrous.’ Everything must be entertained as what it manifestly seems to be. Nothing can be regarded as ‘surprising,’ any more than anything can be regarded as ‘miraculous.