Converse argument: swapping antecedents and consequents
Pencil ratios 8-4, 6-3 rearranged to demonstrate a converse proportion
In faint pencil Leonardo heads the page 'Converse argument' and works the proportional pairs 8/4 and 6/3, noting that here the antecedents are exchanged into consequents. A further step recasts the terms as 8/4 and 6/3, then 12/9 over 4/3, exploring how the ratios behave when their order is reversed. Light bracket sketches accompany the numbers, in keeping with the balance and proportion studies on the neighbouring leaves.
On this page
Exchanging antecedents into consequents
Under the heading 'Converse argument' the pairs 8/4 and 6/3 are restated, with the note that here the antecedents are swapped into consequents. A following line pairs 12/9 over 4/3, testing how the proportion holds when the terms are reversed.