Book, Paragraph

 1  II, 2 |  contain surfaces and volumes, lines and points, and these are
 2  II, 2 | geometry investigates physical lines but not qua physical, optics
 3  II, 2 |      investigates mathematical lines, but qua physical, not qua
 4 III, 6 |      the theory of indivisible lines.) The alternative then remains
 5  IV, 11|      of the line-for it is two lines that are parts of one line.~
 6  IV, 13|        it is with mathematical lines. For the intellect it is
 7   V, 3 |     succession, e.g. a line or lines if it is a line, a unit
 8   V, 3 |        between points (for all lines are intermediate between
 9  VI, 6 |  division is infinite, just as lines may be infinitely divided
10  VI, 9 |        proceeds along the same lines as the bisection-argument (
11 VII, 4 |      one and the same.) If the lines are specifically different,
12 VIII, 8|       in number-or some on the lines of this same argument put