Franz Brentano_The True and the Evident.pdf

40
The True and the Evident
is basic and fundamental, the condition of all thought and of all certainty. Here one can
speak only of direct evidence; one cannot even say that the thought is necessary, for it is
prior to all necessity. Equally direct and evident is the conscious certainty that I think this
or that; it is inextricably interwoven with my self-conscious in such a way that the one is
given with the other.”) Given the doctrines previously considered, this would seem to be a
contradictio in adjecto and thus incapable of defence.
(5) Still more contradictions are to be found in Sigwart’s extraordinary—and
unacceptable—theory of “postulates”, which he contrasts with axioms. The certainty of
axioms is said to lie in the compulsion we have to think in a certain way. But the certainty of
postulates, according to Sigwart, is based upon our practical needs and not upon any purely
intellectual motive (op. cit., pp. 412 ff.). Thus the law of causality, on his view, is a mere
postulate and not an axiom; we take it to be certain because we find that, if we were not to
accept it, we would be unable to investigate nature. But consider now the consequences, for
Sigwart, of his accepting the law of causality in this way: out of sheer good will, he decrees
that like conditions produce like effects; thus he is taking something to be true without any
consciousness of being compelled to do so; but to say this is to contradict Sigwart’s theory
of judgement—unless, of course, taking something to be true is not the same as making a
judgement. So far as I can see, Sigwart has only one way out: he ought to say that he does
not believe any of the postulates, such as that of causation in nature, which he assumes to
be “certain”. But in such a case, he could no longer be serious.
(6) The doctrine of postulates becomes even more questionable if we consider it along
with what we have discussed under (2) above. The consciousness of a universal necessity
to think in a certain way, according to Sigwart, is an axiom and not a postulate. But this
universal necessity to think in a given way is obvious to us only if we apply the law of
causality to our own compulsion to think in that way. Now the law of causality is said to
be a mere postulate and hence to be without evidence. The mark of axioms, according to
Sigwart, is that they involve a universal compulsion or necessity to believe; hence it is
only a postulate that there are such axioms. And therefore what Sigwart calls axioms are
deprived of what they must have, according to him, if they are to be distinguished from
his postulates. All this accords with Sigwart’s remark (section 3) that the belief in the
reliability of evidence is a “postulate”. But given his interpretation of “postulate”, I cannot
imagine how such a remark is to fit in with the rest of the theory.
(7) Sigwart denies that there is any distinction between assertoric and apodictic
judgements (section 31); for, he says, every judgement involves the feeling of necessity.
This assertion must also be attributed to his erroneous conception of judgement; he would
seem to identify the feeling, which he sometimes calls the feeling of evidence, with the
nature of apodicticity. But this is to overlook the modal characteristic which distinguishes
some evident judgements from the evident judgements of self-awareness; the law of
contradiction would be an instance of the former, the judgement that I exist an instance of
the latter. The former exemplifies what is “necessarily true or necessarily false”, the latter
what is only “actually true or false”. Both are evident, however, and in the same sense of
the word, and they do not differ with respect to certainty. It is only from judgements of the
former sort, not from those of the latter sort, that we acquire the concepts of impossibility
and necessity.