In un concepto varïati effetti. Dante and Cecco d’Ascoli on embryology, astrology and the nobility of offspring

In their respective reflections on nobility and individual differences, Dante and Cecco d’Ascoli invoke the example of twins, arguing that one twin may be ‘noble’ while the other is not. The embryological premises supporting this conclusion, however, diverge sharply. Dante, following Aristotle, advances a fundamentally ‘philosophical’ theory of generation. Cecco, by contrast, draws on a medical repertoire that ranges from the doctrine of the double seed and the seven ‘cells’ of the uterus to ‘astrological’ organogenesis and even superfetation. Their dispute over nobility therefore leads to distinct outcomes: Cecco continues to conceive of nobility, in the customary fashion, as a virtue, whereas Dante – at least in the Banquet – treats it as the natural root of the virtues. Above all, their opposing positions expose two further loci of disciplinary contention: one between philosophy and medicine, the other between philosophy and astrology. The case of twins thus reaffirms its status as a privileged ‘epistemological laboratory’, legitimising the emergence of individual differences from natural conditions that are, at least apparently, perfectly identical – “In un concepto varïati effetti,” as Cecco succinctly puts it.