properties and powers, and that their respective operations exactly correspond to each other by virtue of a "preestablished harmony" between the two, just as one clock may be so adjusted as to keep time with another, although each has its own moving power, and neither receives any part of its motions from the other. This theory, therefore, denies everything like causal action between mind and matter; and when it is extended, as it may legitimately be, to the relation between God and the world, it would seem to imply the coequal existence and independence of both, and the impossibility of any causal relation between the two. The manifest defects of these theories have given rise to a _third_, which, in one of its forms, has been generally adopted by Divines,--the theory of "instrumental causes." This theory has assumed two distinct and very different forms. In the first, all natural effects are ascribed to powers _imparted_ to created beings, and _inherent_ in them; that is, to powers which are supposed to have been conferred at the era of Creation, and to be still sustained by God's will in Providence, subject, however, to be suspended or revoked according to His pleasure. In the second, which resembles in some respects the doctrine of "occasional causes," all natural effects are ascribed to powers not _imparted_, but _impressed_, not belonging to the natural agent, but communicated by impulse _ab extra_; and God's will is represented as the only efficient cause in Nature. In both forms of the theory, the agency of God and the instrumentality of natural means are, in a certain sense, acknowledged; but in the _former_, second causes are apt to be regarded as if they were self-existent and independent of God; in the _latter_, second causes are apt to be virtually annulled, and all events to be regarded as the immediate effects of Divine volition. Both extremes are dangerous. For, on the one hand, the operation of second causes cannot be regarded as necessary and independent, without severing the tie which connects the created universe with the will of the Supreme; and, on the other hand, the operation of second causes cannot be excluded or denied, without virtually making God's will _the only efficient cause_, and thereby charging directly and immediately on Him, not only all the physical changes which occur in Nature, but also all the volitions and actions of His creatures. In order to guard against these opposite and equally dangerous extremes, we must hold the real existence and actual operation of "second causes;" while we are careful, at the same time, to show both that whatever powers belong to any created being were originally conferred by God, and also that they are still preserved and perpetuated by Him, subject to his control, and liable to be suspended or revoked, according to the pleasure of His will. We would thus have _one First_, and MANY SECOND CAUSES; the former