They seem to have been apprehensive that by ascribing any peculiar properties or active powers to matter, they might incur the hazard of weakening the grounds on which they contended for the spirituality of man and the supremacy of God.

Thus, in the "Inquiry into the Nature of the Human Soul," by Andrew Baxter, the existence of any active property or power in matter is explicitly denied, and the only property which is ascribed to it is a certain passive power, or "vis inertiae," by which it is incapable of changing its state, whether of rest or of motion.

This "vis inertiae" is not only supposed to be the sole property of matter, but is even held to be inconsistent with, and exclusive of, any active power whatever; and all the effects which are usually said to be produced by it are ascribed to the power of an immaterial Being.

We are told that "vis inertiae," or "a resistance to any change of its present state, is essential to matter, and inconsistent with any active power in it;" that "all gravity, attraction, elasticity, repulsion, or whatever other tendencies to motion are observed in matter (commonly called natural powers of matter), are not powers implanted in matter or possible to be made inherent in it, but impulse or force impressed upon it _ab extra_;" and that "the cause of its motion must be sought for in something not matter, in some _immaterial cause or being_."-- "Gravity," for instance, "is not the action of matter upon matter, but the virtue or power of an immaterial cause or being, constantly impressed upon it." Nor has this doctrine been confined to such metaphysical reasoners as Andrew Baxter.
Professor Playfair tells us, that when he was introduced to Dr.Horsley, the Bishop "expressed great respect for Lord Monboddo, for his learning and his acuteness, and (what was more surprising) for the soundness of his judgment.

He talked very seriously of the notion of _mind being united to all the parts of matter and being the cause of motion_.