metic then harmonic science, and that which consists of fewer things than that which is from addition, as arithmetic than geometry. I mean by "from addition," as unity is a substance without position, but a point is substance with position, this is from addition.
Chapter 28
One science is that which is of one genus of those things which are composed of first (principles), and are the parts or affections of these per se; but a science is different from another, whose principles are neither from the same things, nor one from the other. A token of this is when any one arrives at things indemonstrable, for it is necessary that they should be in the same genus with those that are demonstrated; it is also a sign of this when things demonstrated through them are in the same genus and are cognate.
Chapter 29
There may possibly be many demonstrations of the same thing, not only when one assumes an
