We have examined as to the amount of knowledge to be gained from these sources in regard to the nature of mind, the laws of the system of which it is the essential part, the immortality of the soul, our prospects after death, and the character and designs of our Creator. In discussing the last topic, it has been assumed that the grand and ultimate design of the Creator is "to produce the greatest possible happiness with the least possible evil." We have examined, at some length, the chief faculties and laws of the human mind, for the purpose of exhibiting their adaptation to this design. We now proceed to a brief review of this portion as a _summing up_ of the evidence sustaining the proposition that the grand end of the Creator, in forming mind, is _to produce the greatest possible happiness with the least possible evil_. As preliminary, however, we need to refer to one principle. Whenever we find any contrivances all combining to secure a certain good result, which, at the same time, involves some degree of inevitable evil, and then discover that there are contrivances to diminish and avoid this evil, we properly infer that the author intended to secure _as much of the good with as little of the evil as possible_. For example, a traveler finds a deserted mine, and all around he discovers contrivances for obtaining gold, and, at the same time, other contrivances for getting rid of the earth mixed with it. The inevitable inference would be that the author of these contrivances designed to secure as much gold with as little earth as possible; and should any one say that he could have had more gold and less earth if he wished it, the answer would be that there is no evidence of this assertion, but direct evidence against it. Again: should we discover a piece of machinery in which every contrivance tended to secure _speed_ in movement, produced by the _friction_ of wheels against a rough surface, and at the same time other contrivances were found for diminishing all friction that was useless, we should infer that the author designed to secure the _greatest possible speed_ with the _least possible friction_.