After concluding the Latin version of
his logic, Wolff moved on to translate his metaphysics. Just like
with logic, the latinization added a huge amount of pages to the
German version. Thus, Wolff actually divided his metaphysics into
five parts, each corresponding to a chapter in the German
metaphysics. This series begins with Prima philosophiae, sive
ontologia, Wolff's Latin take on
ontology.
As a careful reader
might notice, there is no book corresponding to the first chapter of
German metaphysics, the Cartesian beginning establishing the
existence of human consciousness. Instead, Latin ontology begins with
a general examination of the nature of ontology. Like the title of
the book says, ontology is primary or first philosophy, on which all
other philosophical disciplines should be based. This means that even
logic or the very methodology of science is based in Wolffian scheme
on ontology. What Wolff means is apparently that we couldn't be doing
science, or indeed, doing anything, if we, among other things, did
not exist.
The description of
ontology as a philosophical discipline is also important. Just as we
can distinguish natural logic or natural means of cognizing from
philosophical or artificial logic, similarly there is a natural
ontology, or in other words, we humans have a natural tendency to
categorize and conceptualize things that exist. Just like natural
logic was not enough for Wolff, he is certain that natural ontology
also requires some improvement. This was already attempted in
scholastic philosophy, which tried to define ontological concepts
more carefully. Yet, scholasticism was sterile, Wolff thinks, and the
reason of its sterility was hidden in its lack of scientific form.
That is, Wolff explains, scholastics failed to base their ontology on
demonstrations starting from evident axioms and reliable experiences.
Wolff's evident
attempt is to fix the mistake of scholasticism and to base his
ontology on the most certain principle of contradiction. As one might
remember, in German metaphysics Wolff wanted to justify the principle
through the Cartesian beginning of the whole book: if the principle
wouldn't have worked, neither would have the beginning been
indubitable. Here Wolff does not have the luxury of assuming the
existence of anything. Yet, he also does not just want to accept the
principle dogmatically, but tries to give some justification for his
position. Wolff's justification is what would later be called
psychologistic or it bases theories of what there is on assumptions
of what (human) mind can do. Anyone would notice that we cannot think
of one thing having two sets of contradictory predicates at the same
time, Wolff remarks. The easiest way to explain this is to assume
that this repugnant nature of contradiction just follows an
ontological truth: things really cannot have and not have some
property at the same time.
Indeed, as we
already saw when dealing with German metaphysics, the principle of
contradiction is an ontological and not merely logical principle for
Wolff. What this ontologicity means might be difficult to understand.
In German metaphysics it all ultimately led to God, who thought of
all possible worlds, but could only will one to existence, because
these worlds cancelled one another. Here Wolff is dealing only with
ontology and God must still be left out of the equation.
Instead of God,
Wolff then bases the principle on what is ontologically primary
according to him, that is, individual things – Wolff is a committed
nominalist denying the literal existence of e.g. universals.
Individual things then cannot have a property (e.g. redness) and at
the same time not have it, that is, have a property cancelling the
first one (blueness or any other colour beside redness). Possible
characteristics, as it were, battle over individual objects and just
by their presence exclude other characteristics. It is then redness
of this individual that contradicts blueness of the same individual,
and the more general contradiction between e.g. redness of all members of
a genus and blueness of one member of this genus is just an
abstraction out of the concrete relations between individuals.
Yellow and white battling over the supremacy of the ball surface. |
Although the
principle of contradiction should be the highest principle of
philosophy, Wolff does not mean that all things could be proved from
it – we just have to remember the possibility of using indubitable
experiences as further premisses. Yet, he is willing to allow that we
can deduce something out of it. For instance, Wolff thinks that the
principle of identity, ”what is, is what it is” could be easily
derived from the principle of contradiction. Indeed, one would hardly
want to deny that the two principles are quite closely related. Well,
Kant did deny this, but he was probably reading the principles in a strict logical sense: because negating and affirming are two different
activities, there must be different principles governing them.
Ontologically, on the other hand, it seems more reasonable that by
excluding certain characteristics a thing must presents others.
A more difficult to
explain is Wolff's willingness to deduce the principle of excluded
middle from the principle of contradiction, especially as we know
that the two principles are actually independent of one another. How
so, you ask? Think of the principle of contradiction saying that a
proposition cannot have both the values 1 or true and 0 or false and
the principle of excluded middle saying that its only possible values
are 1 and 0: then the first principle does not preclude the
possibility of a proposition having a third value (say, ½), while
the second principle does not say that it couldn't have two values at
the same time.
Judging by Wolff's
actual proof of the principle of excluded middle, it appears that
there's a hidden ontological presupposition behind it. We are still
thinking of individual objects and their possible characteristics.
Now, denial of one characteristic of a thing (say, redness) means
just insurgence of another characteristic of the same type within this
thing (say, blackness). In other words, there are no bare or
characterless particulars in Wolffian scheme of things. Then the law
of excluded middle becomes a triviality. If you would deny a property
A of a thing, this means that another property of the same sort, but
incompatible with A arises, and if you deny property non-A, that is,
all the properties of the same type than A, but incompatible with it,
then A itself must arise. Thus, if you deny both A and non-A, you are
actually also letting both A and non-A exist within the same
individual thing, which then contradicts the principle of
contradiction.
The most famous is
undoubtedly Wolff's apparent attempt to deduce the principle of
sufficient reason/ground from the principle of contradiction. I
myself have already tackled the issue earlier, but I think the topic
deserves a second chance. But that's something for the next post.
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