be something purely logical.)

6.33 We do not have an a priori belief in a law of conservation, but
rather a priori knowledge of the possibility of a logical form.

6.34 All such propositions, including the principle of sufficient
reason, tile laws of continuity in nature and of least effort in nature,
etc. etc.--all these are a priori insights about the forms in which the
propositions of science can be cast.

6.341 Newtonian mechanics, for example, imposes a unified form on the
description of the world. Let us imagine a white surface with irregular
black spots on it. We then say that whatever kind of picture these make,
I can always approximate as closely as I wish to the description of it
by covering the surface with a sufficiently fine square mesh, and then
saying of every square whether it is black or white. In this way I shall
have imposed a unified form on the description of the surface. The form
is optional, since I could have achieved the same result by using a net
with a triangular or hexagonal mesh. Possibly the use of a triangular
mesh would have made the description simpler: that is to say, it might
be that we could describe the surface more accurately with a coarse
triangular mesh than with a fine square mesh (or conversely), and so on.
The different nets correspond to different systems for describing the
world. Mechanics determines one form of description of the world by
saying that all propositions used in the description of the world must
be obtained in a given way from a given set of propositions--the axioms
of mechanics. It thus supplies the bricks for building the edifice of
science, and it says, 'Any building that you want to erect, whatever it
may be, must somehow be constructed with these bricks, and with these
alone.' (Just as with the number-system we must be able to write down
any number we wish, so with the system of mechanics we must be able to
write down any proposition of physics that we wish.)

6.342 And now we can see the relative position of logic and mechanics.
(The net might also consist of more than one kind of mesh: e.g. we
could use both triangles and hexagons.) The possibility of describing a
picture like the one mentioned above with a net of a given form tells us
nothing about the picture. (For that is true of all such pictures.)
But what does characterize the picture is that it can be described
completely by a particular net with a particular size of mesh. Similarly
th