But monster and monstrous were most often applied to birth defects and deformities, which seemed (in the absence of knowledge about chromosomes) to be just such warnings or omens. Early modern religious thought often treated deformed births as punishment for wrongdoing, particularly (although not exclusively) in women. As Thomas Watson writes in "The Ten Commandments," part of A Body of Practical Divinity (1692):
God punishes Sabbath-breaking by sudden visible judgements on men for this sin. He punishes them in their estates and in their persons. While a certain man was carrying corn into his barn on the Lord's-day, both house and corn were consumed with fire from heaven. In Wiltshire there was a dancing match appointed upon the Lord's-day; and while one of the company was dancing, he suddenly fell down dead. The 'Theatre of God's Judgements' relates of one, who used every Lord's-day to hunt in sermon-time, who had a child by his wife with a head like a dog, and it cried like a hound. His sin was monstrous, and it was punished with a monstrous birth.As the discussion of monstrosity moved from theological to philosophical and scientific discourse, there were attempts to understand these seeming violations of natural law. John Locke's Essay concerning Humane Understanding (1690), for instance, confronts the difficulties monsters pose for philosophical classifiction. In considering the question of essences, he writes:
Concerning the real essences of corporeal substances ... [the suggestion that] these essences as a certain number of forms or moulds, wherein all natural things that exist are cast, and do equally partake, has, I imagine, very much perplexed the knowledge of natural things. The frequent productions of monsters, in all the species of animals, and of changelings, and other strange issues of human birth, carry with them difficulties, not possible to consist with this hypothesis; since it is as impossible that two things partaking exactly of the same real essence should have different properties, as that two figures partaking of the same real essence of a circle should have different properties. (Book III, chapter 3)He elaborates several chapters later in a discussion of "The Names of Substances":
14. Difficulties in the supposition of a certain number of real essences. To distinguish substantial beings into species, according to the usual supposition, that there are certain precise essences or forms of things, whereby all the individuals existing are, by nature distinguished into species, these things are necessary:--And the monster appears prominently in various eighteenth-century works on physical anthropology and taxonomy. The racial categories of Linnaeus, for instance, included "Monstrous," "Ferus" (fierce, bestial) and "Troglodytes" along with "Americanus," "Europaeus," "Asiaticus," and "Afer" (African).
15. A crude supposition. First, To be assured that nature, in the production of things, always designs them to partake of certain regulated established essences, which are to be the models of all things to be produced. This, in that crude sense it is usually proposed, would need some better explication, before it can fully be assented to.
16. Monstrous births. Secondly, It would be necessary to know whether nature always attains that essence it designs in the production of things. The irregular and monstrous births, that in divers sorts of animals have been observed, will always give us reason to doubt of one or both of these.
17. Are monsters really a distinct species? Thirdly, It ought to be determined whether those we call monsters be really a distinct species, according to the scholastic notion of the word species; since it is certain that everything that exists has its particular constitution. And yet we find that some of these monstrous productions have few or none of those qualities which are supposed to result from, and accompany, the essence of that species from whence, they derive their originals, and to which, by their descent, they seem to belong. (Book III, chapter 6)
Monsters have a political dimension as well: as Fred Botting argues in "Frankenstein and the Language of Monstrosity,"
Monsters appear in literary and political writings to signal both a terrible threat to established orders and a call to arms that demands the unification and protection of authorised values. Symptoms of anxiety and instability, monsters frequently emerge in revolutionary periods as dark and ominous doubles restlessly announcing an explosion of apocalyptic energy.