In thus presenting plot as the means by which the history of a single soul is externalized, one important element has been excluded from consideration.  The causal chain of events, which constitutes plot, has a double unity, answering to the double order of phenomena in action as a state of mind and a state of external fact.  Under one aspect, so much of the action as is included in any single life and is there a linked sequence of mental states, has its unity in the personality of that individual.  Under the other aspect, the entire action which sets forth the relations of all the characters involved, of their several courses of experience as elements in the working out of the joint result, has its unity in the constitution of the universe,—­the impersonal order, that structure of being itself, which is independent of man’s will, which is imposed upon him as a condition of existence, and which he must accept without appeal.  This necessity, to give it the best name, to which man is exposed without and subjected within, is in its broadest conception the power that increases life, and all things are under its sway.  Its sphere is above man’s will; he knows it as immutable law in himself as it is in nature; it is the highest object of his thoughts.  Its workings are submitted to his observation and experiment as a part of the world of knowledge; he sees its operation in individuals, social groups, and nations, and sets it forth in the action of the lyric, the drama, and the epic as the law of life.  In its sphere is the higher unity of plot by virtue of which it integrates many lives in one main action.  Such, then, is the nature of plot as intermediary between man and his environment, but deeply engaged in the latter, and not to be freed from it even by a purely spiritualistic philosophy; for though we say that, as under one aspect plot shadows forth the unseen world of the soul’s life, so under the other it shadows forth the invisible will of God, we do not escape from the outward world.  Sense is still the medium by which only man knows his brother man and God also as through a glass darkly,—­

    “The painted veil which those who live call life.”

It separates all spirits, the beautiful but dense element in which the pure soul is submerged.

It is necessary only to summarize the characteristics of plot which are merely parallel to those of type already illustrated.  Plot may be simple or complex; it may be more or less involved in physical conditions in proportion as it lays stress on its machinery or its psychology; it must be important, as the type must be high, but important by virtue of its essential human meaning and not of its accidents; it is a fragment of destiny only, but in this falls in with the way life in others is known to us; if it passes into the superhuman world, it must retain human significance and be brought back to man’s life by devices similar to those used in the type for the same purpose; it rises in value in proportion to the universality it contains, and gains depth and permanence as it is interpretative of common human fate at all times and among all men; it may be purely imaginary or founded on actual incidents; and its exemplary interpretation of man’s life is its substance, and constitutes its ideality.