Proof and Persuasion

Pharmacy, Testing, and the Language of Truth in Renaissance Italy

“…If we wish to make sense of how sixteenth-century Italian apothecaries understood their work, we need to appreciate that their mode of validation, of proof and persuasion, 167 was based not on notions of efficacy and novelty, but of authenticity. This explains the particular brand of testing examined and the values sustaining it.…”

Rhetoric and Psychology

“…The orator's ethos had a decisive effect (pathe) upon the souls of the audience, namely, to induce belief (pistis) in them. In spite of many innovations, this framework provided by classical rhetoric remained highly respected in the early modern period; so did the attendant awareness of complex relationships and porous boundaries between logic and the art of rhetorical reasoning (Vickers 1988;Moss 1993;Serjeantson 2006).…”

“…The early modern study of nature entailed a fundamental shift in the understanding of what truth is and how it should be sought in nature. Increasingly during the sixteenth and seventeenth centuries, forms of proof that were traditionally derived from and applied to the human sciences (law, ethics, politics) became transferred to the study of nature (Serjeantson 2006). Yet this created a problem, since rhetorical forms of reasoning only generate proofs which are probable (when, say, a witness is testifying in a court of law, and the jury pronounces its verdict on that testimony).…”

Forms of Persuasion: Kepler, Galileo, and the Dissemination of Copernicanism

“…63 Fides, alternatively translated as credit, faith, or belief, was the method by which ancient rhetoricians evaluated the credibility of witnesses and their testimony. 64 It was also a standard applied in a number of early modern disciplines, among them the artes historicae, 65 but also the discipline of law. Kepler relied on this latter linkage, and in the face of opposition to Galileo's discoveries, and of the misreading of his own text, he explicitly reframed the entire debate as a legal one.…”