The St Andrews medieval logic reading group has been working its way through Part II Fascicule 6 of the Logica Magna, which is on the truth and falsity of propositions. In the discussion of the Eighth Way (identified as Peter of Mantua’s by Francesco del Punta), which stems from the following two rules:
- A true proposition is an indicative, perfect univocal expression through which the intellect is adequately rendered correct.
- A false proposition is an indicative, perfect univocal expression through which the intellect is not adequately rendered correct.
Paul gives us the following very strange argument, that this Way “asserts that no one can think of non-being, nor can anyone think of what is not thought of”.
For he [presumably Peter of Mantua] argues as follows: Precisely being can be thought of. Therefore, non-being cannot be thought of. The premiss is clear, since being can be thought of and nothing that is not a being can be thought of. The opposite implies a contradiction. Similarly, he proves that only what is thought of can be thought of, from which he concludes that what is not thought of cannot be thought of [p. 59, emphasis added].
I can guarantee that this is the strangest philosophical position you’ll see this week.