Handbook of the History of Logic: - Fordham University Faculty

526 Simo Knuuttila
a disjunction implies that the disjuncts are necessary or determinate. 69 This is
close to what Mignucci regards as Boethius’s position.
The commentary on De interpretatione 9inLogica ‘Ingredientibus’ involves
Abelard’s most detailed analysis of the structure of Aristotle’s argument. Chapter
9 is described as a dialectical discussion of the thesis that in all contradictories one
part is necessarily true and the other false. The correct reading of this is that of
all contradictory pairs necessarily one part is true and the other false. This does
not imply that one is necessarily true and the other necessarily false, although one
is true and the other false. 70
Abelard pays attention to some propositions about past and present states of
affairs the truth and falsity of which depend on future, such as ‘Socrates is the
name of a man going to eat tomorrow’ or ‘He has spoken falsely’, when this is
said of a man who said yesterday that Socrates will eat tomorrow. The truth and
falsity of propositions of this kind are not knowable without knowledge of future
contingent states of affairs which are indeterminate and epistemically inaccessible
to human beings. Hence the propositions have an indeterminate truth and falsity
and do not differ from future contingent propositions in this respect. In discussing
these examples, Abelard states that ‘Aristotle calls propositions determinately or
indeterminately true with respect to the determinate or indeterminate states of affairs
they propose’. This terminology is part of Abelard’s rational reconstruction
of Aristotle’s discussion; being probably aware that Aristotle did not use these
terms at all, Abelard suggests that Aristotle would consider propositions indeterminately
true or false if their truth depended on indeterminate future contingent
states of affairs. Propositions which propose the actual inherence of truth in a future
contingent proposition are of the form: “Socrates will eat tomorrow’ is true’.
As far as determinateness is understood in accordance with what Abelard calls
Aristotle’s view, this is no more determinate than ‘Socrates will eat tomorrow’.
As for the truth as a present fact, Abelard repeats the remark from the Dialectica
that one could call this present state of affairs determinate and, correspondingly,
the propositions determinately true or false. In this sense all true propositions
are determinately true, but this has nothing to do with causal determination.
Abelard also remarks that God knows whether any proposition is true and false,
and all true propositions are determinately true with respect to this omniscience.
The determinateness in the sense of divine knowability pertains to truth-values
and truth-makers, but this supranatural knowability does not make things necessary.
71 While the truth-values of these propositions are in principle knowable,
human beings cannot know them without supranatural illumination. The present
truth of a future contingent proposition implies that what is predicted will obtain
but not that it is determinate, since future contingent states of affairs are inde-
69 Dialectica 211.28-32; 212.36-213.7; 221.15-24.
70 Logica ‘Ingredientibus’ 431.13-432.9; 445.22-446.29.
71 Logica ‘Ingredientibus’ 421.28-422.30. For truth and determinateness in Abelard, see also C.
Normore, ‘Future Contingents’ in N. Kretzmann, A. Kenny, J. Pinborg (eds.), The Cambridge
History of Later Medieval Philosophy (Cambridge: Cambridge University Press, 1981), 362-3;
N.T. Lewis, ‘Determinate Truth in Abelard’, Vivarium 25 (1987), 81-109.