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.
The Co-operating cause further aids the Synectic, in the way of intensifying what is produced by it. But the Joint-cause does not fall under the same notion. For a thing may be a Joint-cause, though it be not a Synectic cause. For the Joint-cause is conceived in conjunction with another, which is not capable of producing the effect by itself, being a cause along with a cause. And the Co-operating cause differs from the Joint-cause in this particular, that the Joint-cause produces the effect in that which by itself does not act. But the Co-operating cause, while effecting nothing by itself, yet by its accession to that which acts by itself, co-operates with it, in order to the production of the effect in the intensest degree. But especially is that which becomes co-operating from being Procatarctic, effective in intensifying the force of the cause.
