Page:Mind (New Series) Volume 6.djvu/473

 this disturbance, viz., of the re-approach to the maximum of maintenance?

The environment, which is primarily hostile, must nevertheless be regarded also as favourable to maintenance, as maintaining, in so far as it is considered as training the individual in habitual modes of behaviour; and this concerns not only the environment in particular factors, not particular R-values, but all together. The same stimuli which condition a vital disturbance, contribute also to maintenance, and vice versâ. Work, for instance, is not an exclusively destructive factor; while, on the other hand, nourishment is not an exclusively maintaining factor. This is proved by the fact that an organism degenerates and finally perishes just as much when it is merely nourished (without being subjected to work), as when it merely works (without being also nourished).

Our maintenance is then conditioned by an equilibrium between a customary work-process, and a customary nourishment-process. On the other hand, by the preponderance of the one factor over the other, viz., by an alteration in the amount of exercise of one of the two factors, a deviation of system C from this equilibrium of the maintenance-maximum is given, and this deviation Avenarius calls a vital-difference.

Now this is a very important conception, for by placing our whole life with all its action and thought in relation to the vital maintenance-maximum, we can comprehend this action and thought also in its totality as depending upon such vital-differences and their annulment. “Life” is not inaction and rest, but movement; and movement is here equivalent to continual oscillation about an ideal point of rest.

Thus the process of change in the nervous central organ begins with the vital-difference; with the annulling of the vital-difference the process of change in each particular case attains its end. All the changes which lie between this beginning and end follow each other immediately; they form a series, which Avenarius calls the vital-series.

We will first consider the case in which a vital-difference arises as follows: A uniform increase of nourishment may take place in some individual, and may then be annulled by an equally uniform increase of work. Both must be habitual and familiar to the individual in question, and both together form a vital-series of the first order. Thus the vital-series of the first order would be composed in this way:—