A clear difference between Wolff's
Latin and German books of philosophy is that the more extensive Latin
books have also a more detailed structure than their German
counterparts. This is also true of Latin ontology. The book began
with a section detailing the two basic principles of contradiction
and sufficient reason. The second section was then dedicated to
explicating the central notion of essence and some related concepts.
Finally, the third section dealt with several characteristics common
to all entities, such as identity, quantity and truth. Together,
these three sections then formed the first part of Wolff's ontology,
dealing with things in general.
The second and final part of Wolffian
ontology is then about a general classification of things into simple
and complex things. The second part contains, quite naturally, one
section dedicated to complex entities and another dedicated to simple
entities. In addition to these, there's also a section investigating
relations between things, probably just because there was no better
place for it.
Schematics of Wolff's Latin ontology |
Wolff does not add considerable
novelties to his account of complex entities in German metaphysics –
the important fact is that the essence of a complex or composite
entity is based on the essences of its parts and their mutual
relations. Parts are then more essential than their combinations, in
which they still retain their independence.
Now, when we are conscious of such a
combination of several mutually extrinsic things, we see the
combination as extended. In fact, we can abstract from all other
features of the complex things, but this extension, as we do in
geometry. Geometrically we can then define such notions as continuity
(when you cannot put anything else between any two parts of a single
thing) and contiguity (when you cannot put anything between surfaces
of two different things). If two things are not contiguous, one can
also define distance as the shortest line between them.
Extension and related notions can then
be used to define space. As I've said earlier, Wolff follows Leibniz
in accepting the idea of a relational nature of space – space is
determined by certain relations between extended objects (distance
etc.), so that space wouldn't exist without extended things having
those relations. Here Wolff goes even so far to say that absolute
space is just a useful fiction that we abstract from the concrete
relations of complex things – and same goes for absolute time.
A novelty in Wolff's treatment of space
and time in comparison with German metaphysics is that he extends his
account to motion. On the one hand, this means just an extension of
mathematical treatment of space or extended things to moving things.
Lines can be used to describe not just extension, but also motion –
Wolff is here expounding basics of vector calculation.
On the other hand, Wolff also suggests
that if both absolute space and time are fictions, so must absolute
motion be at least partially fictitious. Still, he is not willing to
say that motion is completely imaginary. What is imaginary is the
idea of motion happening in some absolute coordinate system with
fixed places. Instead, motion is just change in the relations of
things – a falling ball is, say, coming closer to the ground.
Furthermore, movement is something
that is sustained by the moving entity – falling ball has impetus
for moving in constant velocity towards the ground. In addition
relations to external things can change the status of movement a
thing has – a ball is constantly accelerated by something in its
fall, and once it has hit the ground, it will stop moving towards the
ground.
So much for complex things and their
characteristics, next time I'll have something to say about simple
things.