Every person, whether consciously or not, gradually builds up, from his observations and reason, a system of philosophy by which he explains, to himself at least, the problems that the new experiences of his life present for solution. It is of great importance, therefore, that, instead of basing one's system of thought upon the contradictory hypotheses of speculative philosophy, we start right, so that our ideas on the questions of life may square with the truth as it is known to the Lord. And these considerations are the excuse for this work.