This manual embraces not only those questions which in our Latin compendia usually are treated of under the heading Theologia Naturalis, but also those which commonly are discussed as a part of Cosmologia. This was done in order to give the necessary completeness to the treatment of my subject. Our English volumes are in the first place intended to help those who do not intend to study in detail Catholic Theology to a sound understanding of the most important questions of Philosophy, and particularly to show them the way to judge intelligently and to solve clearly modern difficulties against those natural truths which form the basis of Christianity. In the celebrated Catholic controversy about the manner of Divine foreknowledge of and concurrence in human actions, it has been my endeavour to give a good account of the opposite opinions and of my own position. I have purposely avoided quotations, as often as I could conveniently without doing harm to the cause of truth, In order to eliminate any element of prejudice or party strife.