Just what is the environment of which an idea is to be formed: i.e., what is the intellectual content or objective detail to be assigned to the term "environment"? It can hardly mean the actual visible environment--the trees, rocks, etc., which a man is actually looking at. These things are there and it seems superfluous to form an idea of them; moreover, the wayfaring man, though lost, would have to be an unusually perverse fool if under such circumstances he were unable to form an idea (supposing he chose to engage in this luxury) in agreement with these facts. The environment must be a larger environment than the visible facts; it must include things not within the direct ken of the lost man; it must, for instance, extend from where he is now to his home, or to the point from which he started. It must include unperceived elements in their contrast with the perceived. Otherwise the man would not be lost. Now we are at once struck with the facts that the lost man has no alternative except either to wander aimlessly or else to _conceive_ this inclusive environment; and that this conception is just what is meant by idea. It is not some little psychical entity or piece of consciousness-stuff, but is _the interpretation of the locally present environment in reference to its absent portion_, that part to which it is referred as another part so as to give a view of a whole. Just how such an idea would differ from one's plan of action in finding one's way, I do not know. For one's plan (if it be really a plan, a method) is a conception of what is given in its hypothetical relations to what is not given, employed as a guide to that act which results in the absent being also given. It is a map constructed with one's self lost and one's self found, whether at starting or at home again, as its two limits. If this map in its specific character is not also the only guide to the way home, one's only plan of action, then I hope I may never be lost. It is the _practical_ facts of being lost and desiring to be found which constitute the limits and the content of the "environment."