Viewed in this light, the course of Providence is wonderfully adapted to the constitution of human nature, since it affords as much _certainty_ in regard to some things as is sufficient to lay a foundation for forethought, prudence, and diligence in the use of means, and yet leaves so much remaining _uncertainty_ in regard to other things as should impress us with a sense of constant _dependence_ on Him "in whom we live, and move, and have our being." The constitution of Nature and the course of Providence in the present state seem mainly intended to teach these _two_ lessons,--first, of _diligence_ in the use of means, and, secondly, of _dependence_ on a Higher Power: for there is sufficient _regularity_ in the course of events to encourage human industry in every department of labor; and yet there is as much _uncertainty_, arising from the endless complication of causes and the limited range of human knowledge, as should impress us with a sense of our utter helplessness. The wisdom of God in the government of the world may be equally manifested in the _regular order_ which He has established, and which, within certain limits, man may be able to ascertain and reckon on as a ground of hopeful activity; and in the _apparent casualty_ and _inscrutable mystery_ of many things which can neither be divined by human wisdom, nor controlled by human power. It matters not whether the remaining uncertainty is supposed to arise from some classes of events not being subject to regular laws, or from our ignorance of these laws, and the variety of their manifold combinations. In either case, it is certain that, in our actual experience, and, so far as we can judge, in the experience of every creature not possessed of omniscient knowledge, these two elements are and must be combined,--such a measure of _certainty_ as should encourage industry in the use of means, and such a measure of remaining _uncertainty_ as should keep them mindful that they are not, and never can be, independent of God. SECTION III. THE EFFICACY OF PRAYER. The doctrine of Providence lays a firm foundation for the duty of Prayer. In the case of all intelligent, moral, and responsible beings, the mere existence of a Divine government to which they are subject, would seem to imply an obligation to own and acknowledge it; and this obligation is best fulfilled by the exercise of prayer, which is a practical testimony alike to man's _dependence_ and to God's _dominion_.