In the chapter just concluded, the field of ethics is termed a "universe." In the chapter upon Theodicy, it was noted that in Lincoln's most thoughtful ponderings, the great world of reality that passes under the name of physics, or the physical world, seemed to lie outside the field of his concern. Here is a matter demanding something more than a bare allusion. The ponderable universe of material things has impressive majesty. It is too solid and real and present in our life to be ignored. Among the stars and beneath the hills and within the seas are solid and substantial verities. We are environed by their influences on every side. It is deep within their strong embrace that our predetermined fate is being continuously unrolled. What can be the scope and what must be the value of any view of ethics or any plan of life in which this solid, ever-present, all-embracing material world is so indifferently esteemed? It is with just this query in mind that this research into the mind of Lincoln was first conceived. And the query which has been throughout in immediate review, but unpropounded openly as yet, now demands to be defined and scrutinized. Did the mind of Lincoln, engrossed as it was upon interests supremely ethical, and ignoring, as it seemed to do, all those vast and deep complexities of the purely physical world, find for our unquiet human thought the true and perfect equilibrium? Or was the thought of Lincoln unbalanced and incomplete, misguided and inadequate essentially? In brief, how must ethics and physics, these two and only two supreme realities, when each is most fairly understood, be conceived to correlate and harmonize? As between these two realities, each so imperial and so irreducible, which holds primacy? Here is for any thoughtful mind well nigh the last interrogation. To attain a competent reply the essential qualities of each and either realm must be uncovered and compared. In physics here, and in ethics there, what attributes pervade, abide, and are essential? And, these true qualities being seen in each, as between the two, which proves itself superior; in which does the soul of man find rest?