As their source is not abundant, the dryness sometimes causes delay. There are even periods, in times of aridity, when they dry up altogether. They do not cease to flow from the source, but it is so feebly as to be barely perceptible. These rivers carry little or no merchandise, and, therefore, for the public need, it must be taken to them. It is necessary, at the same time, that art should assist nature, and find the means of enlarging them, either by canals, or by the help of other rivers of the same kind, which are joined together and united to it, which rivers thus joined increase the body of water, and, helping each other, put themselves in a condition to carry a few small boats, not to the sea, but to some of the chief rivers, of which we shall speak later. Such beings have usually little depth of spiritual life. They work outwardly, and rarely quit their meditations, so that they are not fit for great things. In general they carry no merchandise--that is to say, they can impart nothing to others; and God seldom uses them, unless it be to carry a few little boats--that is, to minister to bodily necessities; and in order to be used, they must be discharged into the canals of sensible graces, or united to some others in religion, by which means several, of medium grace, manage to carry the small boat, but not into the sea itself, which is God: into that they never enter in this life, but only in the next. It is not that souls are not sanctified in this way. There are many people, who pass for being very virtuous, who never get beyond it, God giving them lights conformed to their condition, which are sometimes very beautiful, and are the admiration of the religious world. The most highly favoured of this class are diligent in the practice of virtue; they devise thousands of holy inventions and practices to lead them to God, and to enable them to abide in His presence; but all is accomplished by their own efforts, aided and supported by grace, and their own works appear to exceed the work of God, His work only concurring with theirs.