678 THE AMERICAN JOURNAL OF SOCIOLOGY
their existence, together with a delineation of their characteristics and affiliations, to the progress of the science.
But, while one may refuse to make the attempt to describe in advance of their exploration the fields of a new science, he might less readily be excused for leaving his readers with no hint as to the general direction his own immediate excursions into those fields may be expected to take. While making no pretense, therefore, to enumerate the common factors which future investigation may find to exist in the different terms of the associational series, some slight attempt will be made to indicate, in a preliminary way, the nature of those common factors, the relations of which to the various forms of the asso- ciational complex this series of papers may be expected to con- sider in due time.
It will be remembered that the subject-matter of sociology was tentatively defined ' to be the activities of living organisms, when these activities are considered from a certain focal point of atten- tion; and that the description and interpretation of these activi- ties, viewed in this orientation, were posited ' as the most immediate task of sociology.
It is significant that among those characteristics of the activ- ities of things which are earliest to command attention, none is more striking than that of their apparent dependence upon antecedent activities. When the consequent activity is that of living matter, we call it a response to the antecedent activity which is considered to be the stimulus of its consequent. Post- poning for the present the consideration of some very important peculiarities of the more intimate nature of this stimulus- organism-response relationship, we have to note here that it obtains generally throughout the whole range of living matter. There is no activity of any organism which can conceivably be without appropriate relations to adequate stimuli. Again, these stimuli are separable into certain great groups and classes. There seems a reasonable possibility, then, that the activities of living matter will themselves be separable into groupings analogous to the groupings of their stimuli ; and, owing to the
■ See p. 675.
