[102] And the number seven by those persons who are in the habit of employing names with strict propriety is called the perfecting number; because by it, everything is perfected. And any one may receive a confirmation of this from the fact, that every organic body has three dimensions, length, depth, and breadth; and four boundaries, the point, the line, the superficies, and the solid; and by these, when combined, the number seven is made up.
But it would be impossible for bodies to be measured by the number seven, according to the combination of the three dimensions, and the four boundaries, if it did not happen that the ideas of the first numbers, one, two, three and four, in in which the number ten is founded, comprised the nature of the number seven. For the aforesaid numbers have four boundaries, the first, the second, the third, the fourth, and three intervals. The first interval being that between one and two; the second, that between two and three; the third, that between three and four.