In the process of scientific discovery, knowledge ampliation is pursued by means of non-deductive inferences. When ampliative reasoning is performed, probabilities cannot be assigned objectively. One of the reasons is that we face the problem of the unconceived alternatives: we are unable to explore the space of all the possible alternatives to a given hypothesis, because we do not know how this space is shaped. So, if we want to adequately account for the process of knowledge ampliation, we (...) need to develop an account of the process of scientific discovery which is not exclusively based on probability calculus. We argue that the analytic view of the method of science advocated by Cellucci is interestingly suited to this goal, since it rests on the concept of plausibility. In this perspective, in order to account for how probabilities are in fact assigned in uncertain contexts and knowledge ampliation is really pursued, we have to take into account plausibility-based considerations. (shrink)

In his Quadratura, Paul of Venice considers a sophism involving time and tense which appears to show that there is a valid inference which is also invalid. His argument runs as follows: consider this inference concerning some proposition A: A will signify only that everything true will be false, so A will be false. Call this inference B. Then B is valid because the opposite of its conclusion is incompatible with its premise. In accordance with the standard doctrine of (...) class='Hi'>ampliation, Paul takes A to be equivalent to 'Everything that is or will be true will be false'. But he proceeds to argue that it is possible that B's premise ('A will signify only that everything true will be false') could be true and its conclusion false, so B is not only valid but also invalid. Thus A and B are the basis of an insoluble. In his Logica Parva, a self-confessedly elementary text aimed at students and not necessarily representing his own view, and in the Quadratura, Paul follows the solution found in the Logica Oxoniensis, which posits an implicit assertion of its own truth in insolubles like B. However, in the treatise on insolubles in his Logica Magna, Paul develops and endorses Swyneshed's solution, which stood out against this ''multiple-meanings'' approach in offering a solution that took insolubles at face value, meaning no more than is explicit in what they say. On this account, insolubles imply their own falsity, and that is why, in so falsifying themselves, they are false. We consider how both types of solution apply to B and how they complement each other. On both, B is valid. But on one (following Swyneshed), B has true premises and false conclusion, and contradictories can be false together; on the other (following the Logica Oxoniensis), the counterexample is rejected. (shrink)

Le argomentazioni presentate in questo volume costituiscono il primo contributo dell’autore al progettato compito di un’analisi e commento completi e puntuali dei principali testi filosofici di Giordano Bruno. Iniziando con il "De umbris idearum" e procedendo con le prime opere in latino, l’autore intende svelare le basi teoretiche della prima speculazione bruniana, destinate ad essere riprese, ampliate ed approfondite nei testi successivi, i "Dialoghi Italiani", così come, in una originale prospettiva atomistica, in quelli latini delle ultime fasi. Il "De umbris (...) idearum" costituisce in questa prospettiva il testo base della difficile e complessa speculazione bruniana: assolutamente lontano – come del resto indicato dalle esplicite affermazioni del filosofo di Nola – dall’impiego pragmatico e retorico della tradizionale arte della memoria, esso piuttosto costruisce progressivamente uno spazio di riflessione di natura ontologica, metafisica e teologica, con influssi sulle considerazioni razionali e naturali. In questo modo l’arte di memoria bruniana diventa la memoria di un arte filosofica civile, la necessità del ricordo di una possibilità del pensiero e della prassi incardinata sulla presenza di un plesso centrale creativo e dialettico, che progressivamente consente l’inserimento della principale innovazione escogitata dalla filosofia bruniana: il concetto dell’infinito. Direttamente tematizzato nei dialoghi in italiano, il concetto creativo e dialettico dell’infinito bruniano separa progressivamente l’autore nolano dalla tradizione neoplatonico-aristotelica, definendo in tal modo uno schema interpretativo della realtà diverso ed opposto rispetto a quello che – oltre l’apparente rivoluzionarietà della scienza moderna – ha innervato i principali sviluppi della civiltà occidentale moderna e contemporanea. (shrink)

This paper argues that three characteristic modern positions concerning intentionality – namely, (1) that intentionality is ‘the mark of the mental’; (2) that intentionality concerns a specific type of objects having intentional inexistence; and (3) that intentionality somehow defies logic – are just three ‘modern myths’ that medieval philosophers, from whom the modern notion supposedly originated, would definitely reject.