Now, if I take any single organism and study it carefully, simply as a biologist or physiologist, I shall recognize in it certain regularities of structure and function and development, upon which I can found various arguments and predictions. I can argue from its general characteristics, to the nature of its environment and habits and modes of life; or from its earlier stages, to what it will be when more fully developed; and these arguments will be quite unaffected by any theory I may hold as to the origin of these changes, and as to the causes of these adaptations. The order and regularity on which my predictions are based is an admitted fact. Theism or materialism are only theories by which that fact is explained. Now, for mind in the abstract, theism is really as much a presupposition of that fact, as the predicted truth is a consequence of it. Both are logically connected with it, and yet neither is derived from it through the other. If, however, we cannot thus observe and calculate on certain regularities and tendencies in the world as we know it, then, not only is the appearance of design and finality an illusion, not only is that particular argument for theism cut away, but with it goes all scientific certainty, all that stands between us and the most hopeless mental and moral scepticism. It is not our immediate concern to prove the value of the "argument from adaptability," but simply to show that it is logically (though not really) unaffected by the question of theism and finality and design. As long as we admit those same effects and consequences of which design is one explanation, but of which others are _prima facie_ conceivable; as long as we hold that the world works on the whole as though it were designed; that the present anticipates and prepares for the future; that the future and absent can be predicted from the present, so long do we hold all upon which the "argument of adaptability" is strictly based. And indeed, as has been said, if once it be admitted that the general progressive tendency on the part of living things is towards a greater harmony and correspondence with surrounding reality, then that argument is a more immediate inference from the existence of an orderly world, than is theism. Though both are strictly independent deductions from the same principle (i.e., from an orderly world), yet theism and the argument from adaptability when once deduced, confirm one another. For it is not hard to show that theism is better adapted to man's higher needs, than atheism or polytheism or pantheism; while if theism be once granted, then, as we said in the last section, the argument from adaptability is much more easily established.