In the first part of this book our studies will be concerned with the meaning of predestination according to Scripture and the teaching of the Church. Then we shall consider the principal difficulties of the problem, the method to be followed, the classification of the theological systems, and the stand taken by St. Augustine. In the second part we shall give the history of the various solutions of the great problem, insisting upon the teaching of St. Thomas, which we shall compare with the tentative solutions proposed by theologians of later date, and especially with the solutions proposed by the post-Tridentine theologians. In the third part we shall treat of grace, especially of efficacious grace, by which the effects of predestination are realized in this life. These are vocation, justification, and merit. We shall make a special study of efficacious grace in its relation to sufficient grace that is offered and even given to all. The scope of this book from beginning to end is the reconciliation of the two principles of divine predilection and possible salvation for all. On the one hand, 'no one thing would be better than another, if God did not will greater good for one than for another'.