LXI. (333) The law also excludes a fourth class, and a fifth, both hastening to the same end, but not with the same intention; for, as they are both followers of the same great evil, self-will, they have divided between them the whole soul as a kind of common inheritance, consisting of a rational and an irrational part; and the one class has appropriate the rational part, which is the mind, and the other the irrational part which is again subdivided into the outward senses; (334) therefore, the champions of the mind attribute to it the predominance in and supreme authority over all human affairs, and affirm that it is able to preserve all past things in its recollection, and to comprehend all present things with great vigour, and to divine the future by probable conjecture; (335) for this is the faculty which sowed and planted all the fertile soil in both the mountainous and champaign districts of the earth, and which invented agriculture, the most useful of all sciences for human life. This also is the faculty which surveyed the heaven, and by a proper contemplation of it made the earth accessible to ships by an ingenuity beyond all powers of description; (336) this, also invented letters, and music, and the whole range of encyclical instruction, and brought them to perfection. This also, is the parent of that greatest of all good things, philosophy, and by means of its different parts it has benefited human life, proceeding by the logical portion of it to an infallible interpretation of difficulties, and by its moral part to a correction of the manners and dispositions of men; and by its physical division to the knowledge of the heaven and the world. And they have also collected and assembled many other praises of the mind on which they dwell, having a continual reference to the species already mentioned, about which we have not at the present time leisure to occupy ourselves.