19. *The union of soul and body, is not a mixture of their substances, as we see bodies united and mixed together, but consists solely in the mutual power that they have of acting upon one another. *If two persons were in such a state of dependance upon one another, that neither of them could act, or move, or think, or feel, or suffer, or desire any thing, without putting the other into the same condition, one might properly say, that they were in a state of strict union, altho’ their substances were not united together. *Now this is the union of the soul and body; the substance of the one cannot be mixed or united with the other; but they are held together in such a state of union, that all the actions and sufferings of the one, are at the same time the actions and sufferings of the other. The soul has no thought or passion, but the body is concerned in it; the body has no action or motion, but what, in some degree, affects the soul. Now, as it is the sole will of God, that is the _cause_ of all the powers and effects which you see in the world; as the _sun_ gives light and heat, not because it has any natural power of so doing; as it is fixed in a certain place, and other bodies moving about it; not because it is in the nature of the sun to stand still, and in the nature of other bodies to move about it; but merely because it is the _will_ of God, that they should be in such a state: as the _eye_ is the organ, or instrument of seeing, not because the _skins_, and _coats_, and _humours_ of the eye, have a natural power of giving sight: as the ears are the organs, or instruments of hearing, not because the _make_ of the ear has any natural power over sounds, but merely because it is the will of God, that _seeing_ and _hearing_ should be thus received; so it is the sole will of God, that is the cause of this union betwixt the soul and the body. 20. If you rightly apprehend this short account of the union of the soul and body, you will see a great deal into the reason of all the outward parts of religion. This union of our souls and bodies, is the reason both why we have so little and so much power over ourselves. It is owing to this, that we have so little power over our souls: for as we cannot prevent the effects of external objects upon our bodies; as we cannot command outward causes; so we cannot always command the inward state of our minds; because, as outward objects act upon our bodies without our leave, so our bodies act upon our minds by the laws of the union vital. And thus you see it is owing to this union, that we have so _little_ power over ourselves.