Its object is especially to emphasise the difference between a true religion of the heart and an outward, formal religion of observances. It is divided into thirteen chapters of varying length, each headed with a caption rather vaguely indicating its contents. After a somewhat long introduction he proceeds to a definition of the human soul, following in the main the lead of the early Fathers, especially of Origen. He distinguishes between the soul of man and a something higher yet, which they describe as spirit. The body is the purely material, the spirit is the purely divine, but the soul, living between the two, belongs permanently to neither, but is tossed back and forth from one to the other according as it resists or gives way to the temptations of the flesh. The body is the harlot, soliciting to evil. "Thus the spirit makes us gods; the flesh makes us beasts; the soul makes us men." This distinction is again and again illustrated, and the chapter ends with a declaration of the true rule of Christian piety; viz., that every man see to it that he judge himself according to his own temptation.[55] [55] v., 20-D. "One man rejoices in fasting, in sacred observances, in going often to church, in repeating psalms, as many as possible--but in the spirit. Now ask, according to our rule, what he is doing:--if he is looking for praise or reward, he smacks of the flesh--not of the spirit. If he is merely indulging his own nature, doing what pleases him, this is not a thing to be proud of, but rather to be feared. There is your danger. You pray and you judge the man who prays not; you fast and you condemn the man who eats. Whoever does not do as you do, you think is inferior to you. Look out that your fasting be not to the flesh! Your brother needs your help, but you meanwhile are mumbling your prayers to God and neglecting your brother's poverty: God will be deaf to such prayers as that.... You love your wife just because she is your wife; that is very little, for the heathen do the same. Or you love her only for your own pleasure; then your love is to the flesh: but if you love her chiefly because you see in her the image of Christ, piety, modesty, sobriety, chastity, then you love her not in herself, but in Christ--nay, you love Christ in her and so God in the spirit." The book then goes on to more specific injunctions to the Christian life, always with the undernote of sincerity as the main thing. Here is a striking passage from the second canon of the eighth chapter:[56] [56] v., 23-A.