But, in truth, Procatarctic causes are more than one both generically and specifically; as, for example, cold, weakness, fatigue, dyspepsia, drunkenness, generically, of any disease; and specifically, of fever. But Synectic causes are so, generically alone, and not also specifically.
For of pleasant odour, which is one thing generically, there are many specific causes, as frankincense, rose, crocus, styrax, myrrh, ointment. For the rose has not the same kind of sweet fragrance as myrrh.
And the same thing becomes the cause of contrary effects; sometimes through the magnitude of the cause and its power, and sometimes in consequence of the susceptibility of that on which it acts. According to the nature of the force, the same string, according to its tension or relaxation, gives a shrill or deep sound. And honey is sweet to those who are well, and bitter to those who are in fever, according to the state of susceptibility of those who are affected. And one and the same wine inclines some to rage, and others to merriment. And the same sun melts wax and hardens clay.
Further, of causes, some are apparent; others are grasped by a process of reasoning; others are occult; others are inferred analogically.
And of causes that are occult, some are occult temporarily, being hidden at one time, and at another again seen clearly; and some are occult by nature, and capable of becoming at no time visible. And of those who are so by nature, some are capable of being apprehended; and these some would not call occult, being apprehended by analogy, through the medium of signs, as, for example, the symmetry of the passages of the senses, which are contemplated by reason. And some are not capable of being apprehended; which cannot in any mode fall under apprehension; which are by their very definition occult.
Now some are Procatarctic, some Synectic, some Joint-causes, some Co-operating causes. And there are some according to nature, some beyond nature. And there are some of disease and by accident, some of sensations, some of the greatness of these, some of times and of seasons.
Procatarctic causes being removed, the effect remains But a Synectic cause is that, which being present, the effect remains, and being removed, the effect is removed.
The Synectic is also called by the synonymous expression “perfect in itself.” Since it is of itself sufficient to produce the effect.
And if the cause manifests an operation sufficient in itself, the co-operating cause indicates assistance and service along with the other. If, accordingly, it effects nothing, it will not be called even a co-operating cause; and if it does effect something, it is wholly the cause of this, that is, of what is produced by it. That is, then, a co-operating cause, which being present, the effect was produced—the visible visibly, and the occult invisibly.
The Joint-cause belongs also to the genus of causes, as a fellow-soldier is a soldier, and as a fellow-youth is a youth.