Probably the word “teleology” does not express the essential character of life at all adequately. Living organisms have the capacity for making for a goal instead of being pushed like inanimate matter, hither and thither by external forces; but the faculty differs from human purpose. E. S. Russell describes the goal-directed activity as follows: “(1) When the goal is reached, action ceases; the goal is normally a terminus of action. (2) If the goal is not reached, action usually persists. (3) Such action may be varied: (a) if a goal is not reached by one method, other methods may be employed; (b) where the goal is normally reached by a combination of methods, deficiency of one method may be compensated for by increased use of other methods. (4) The same goal may be reached by different ways, and from different beginnings; the end-state is more constant than the method of reaching it. (6) Goal-directed activity is limited by conditions, but is not determined by them.” 1