The paper examines controversies over the role of experience in the constitution of scientific knowledge in early modern Aristotelianism. While for Jacopo Zabarella, experience helps to confirm the results of demonstrative science, the Bologna Dominican Chrysostomo Javelli assumes that it also contributes to the discovery of new truths in what he calls ‘beginning science’. Both thinkers use medical plants as a philosophical example. Javelli analyses the proposition ‘rhubarb purges bile’ as the conclusion of a yet unknown scientific proof. Zabarella uses instead hellebore, a plant that is found all over Europe, and defends the view that propositions about purgative powers of plants are based on their ‘identity of substance’, an identity that had become questionable with regard to rhubarb due to new empirical findings in the sixteenth century.
Cf. BuridanIn lib. post. an.2.11.3: “[…] si occurrit tibi alter ignis quem tu non sentis propter memoriam praeteritorum iudicas illum esse calidum et hoc est iam experimentale iudicium de non sensato.” (“[...] if you encounter another fire which you do not feel you judge that it is hot because of your previous memories and this is already an experiential judgment about a thing that has not been perceived.”)
Cf. BuridanIn lib. post. an.2.20.3: “[…] intellectus supplet istam clausulam ‘et sic de singulis’ eo quod numquam vidit instantiam licet consideravit in multis circumstantiis nec apparet sibi ratio nec dissimilitudo quare debeat esse instantia et tunc concludit universale principium.” (“[...] the intellect supplies this clause ‘and thus with regard to particulars’ because it has never seen a counter example although it has considered [sc. the content of the proposition] in differing circumstances and there appears to be no reason or dissimilitude why there should be a counter-example and then it infers the universal principle.”)
BuridanIn lib. post. an.2.20.3: “Cum enim saepe tu vidisti rheubarbarum purgare choleram et de hoc memoriam habuisti et quia in multis circumstantiis diversis considerasti numquam tamen invenisti instantiam tunc intellectus non propter necessariam consequentiam sed solum ex naturali eius inclinatione ad verum assentit universali principio.”
Cf. W. Wissner H. Kating“Botanische und phytochemische Untersuchungen an den europäischen und kleinasiatischen Arten der Gattung Helleborus – I. Zur Verbreitung, Morphologie, Anatomie und Kultur der Helleborus-Arten,”Planta Medica26 (2009) 128–143.