War with vices, but peace with individuals.

Number is divided into even and odd. Even number is divided into the following: evenly even, evenly uneven, and unevenly uneven. Odd number is divided into the following: prime and incomposite, composite, and a third intermediate class (mediocris) which in a certain way is prime and incomposite but in another way secondary and composite.

War with vices, but peace with individuals.

All spiritual growth comes from reading and reflection. By reading we learn what we did not know; by reflection we retain what we have learned. The conscientious reader will be more concerned to carry out what he has read than merely to acquire knowledge of it. In reading we aim at knowing, but we must put into practice what we have learned in our course of study.

In the active life all the vices are first of all to be removed by the practice of good works, so that in the contemplative life a man may, with now purified mental gaze, pass on to the contemplation of the Divine Light.

Prayer purifies us, reading instructs us. Both are good when both are possible. Otherwise, prayer is better than reading.

It is agreed that all sound which is the material of music is of three sorts. First is harmonica, which consists of vocal music; second is organica, which is formed from the breath; third is rhythmica, which receives its numbers from the beat of the fingers. For sound is produced either by the voice, coming through the throat; or by the breath, coming through the trumpet or tibia, for example; or by touch, as in the case of the cithara or anything else that gives a tuneful sound on being struck.