In the development of a theory there
becomes a time, when the ambiguities of academic research become
distilled in the succinct form of a text book. In the development of
Wolffian philosophy this distillation occurred with Thümmig's
Institutiones philosophiae Wolfianae in usus academicos adornatae.
The book appeared in two parts, firs of which dealt with the
theoretical part of Wolff's philosophy – it covers issues dealt in
Wolff's logical, metaphysical and physical works.
Summarising an
intricate philosophical work is undoubtedly an achievement in itself,
but one might wonder how original it can be. Then again, Thümmig's
work was not completely without its novelties. While Wolff himself
had written his main works thus far in German, Thümmig wrote in
Latin, making Wolffian philosophy so available for an international
audience. Indeed, many of the Latin terms used for concepts of
Wolffian philosophy – e.g. ontologia – are fixed for the first
time in Thümmig's work.
An interesting
example of a terminological novelty is the notion of infinite
judgements. In Wolff's logic judgements are divided into affirmative
and negative judgements (respectively, ”A is B” and ”A isn't
B”). Now, Thümmig mentions also a third possibility, where the
form of the judgement is affirmative, but the predicate is negative
(i.e. ”A is not-B”). The notion of infinite judgement was to be
important later on, because it allowed Kant to classify judgements in
triplets according to their quality (more of this when we reach
Critique of pure reason.)
Now, it is
undoubtedly questionable whether these terminological novelties were
truly Thümmig's own inventions: the notion of ontology had appeared
even before Wolffians used it and I suspect that same is true with
the idea of an infinite judgement. Furthermore, it is doubtful
whether Thümmig was really the first Wolffian to use these terms. A
year later Wolff noted in a preface to a work on teleology that
Thümmig's works were essentially faithful representations of Wolff's
own doctrine. This makes one suspect that Wolff himself had already
used the terminology in his lectures and private correspondences and
Thümmig had merely wrote down what Wolff had said.
Whomever the real
innovator is, Thümmig's book does contain in addition to
terminological novelties also some substantial additions to and
reworkings of Wolff's original writings. I shall discuss few of them
in later blog texts, but for now I shall concentrate on the question
of what was the ideal of science in Wolffian school.
Ever since Leibniz
the field of truths had been divided into truths based on the laws of
logic and truths based on empirical facts. Following this division,
Thümmig speaks of a priori and a posteriori cognitions. The
terminology is interesting. At least since Kant, philosophers have
been accustomed to speak of a posterior cognition, based on
experience, and a priori cognition, not based on experience. Now,
this hasn't been the case always. Originally, a priori referred to
reasoning that derived effects from their causes, while a posteriori
reasoning referred to the opposite method of deriving causes from
effects. I am sure that someone has already investigated the topic,
but it would be interesting to know when exactly the two terms
changed their meaning – certainly it happened then before Kant.
For Thümmig, a
posteriori cognition was based in experience, while a priori
cognition was based something called pure reasoning. Experience was
the epitome of intuitive cognition that required a direct intuition
of things. Judgements based immediately on intuitions concerned
always individual things, and experience was a sort of generalization
from intuitive judgements. The transition was possible, because at
least the predicates of intuitive judgments were general and
therefore even they had something to do with generalities. Thus, by
knowing properties shared by many individuals we could discover
empirical laws connecting certain general properties.
Pure reasoning, on
the other hand, was the high point of symbolic cognition, which used
words or other symbols to stand for things themselves. Reasoning in
general had to do with making discursive judgements, that is,
judgements deduced from other judgements by means of syllogisms.
Reasoning was pure, when among the starting points of deduction there
was no intuitive judgement, but everything was based on mere
definitions and self-evident axioms.
As it was common at
the time, Thümmig characterized mathematics as the primary example
of a priori cognition – both Hume and Leibniz would have agreed
that mathematics was based on self-evident axioms. We have seen that
Rüdiger had criticized such an idea, because at least geometry
appeared to have an intuitive aspect. Kant in a sense struck a
compromise between the two positions, because on his opinion
mathematics is both a priori and intuitive – here Kant had
obviously changed the meaning of a priori and intuitive.
A primary example
of a posteriori science is for Thümmig physics. Although Wolff and
Wolffians were mistakenly thought to disparage empirical matters, we
can immediately see that over half of Thümmig's book is dedicated to
physical and hence empirical questions.
A more intriguing
problem is where in the classification metaphysics should be
situated. We have seen that Wolff at least apparently tried to
axiomatize at least a major portion of metaphysics: everything begins
from the self-evident principle of non-contradiction, while even the
crucial principle of sufficient reason is supposedly deduced from it.
Thümmig, on the
other hand, does not even mention this deduction. Instead, he
emphasizes the justification that Wolff had barely mentioned – the
principle of sufficient reason is required so that we can distinguish
between a dream and reality. Thümmig thus apparently bases the main
principle of metaphysics on an empirical proposition.
Does that make
Thümmig's version of Wolffian metaphysics then a posteriori? Not
necessarily. The possibility to distinguish dreams and reality is in
a sense a necessary presupposition of even having experiences. We
might hence interpret the justification as transcendental –
metaphysics would then be synthetic a priori in the Kantian sense.
Next time I'll be
looking at Thümmig's metaphysics in a more detail.
