with the least possible expenditure of thought."[1] That is, the aim of science is to give such a conceptual description of experience as shall be most comprehensive and readily intelligible.
"With this in mind let us make science the object of a psychological inquiry. It seems evident enough that the mind is an instrument for accomplishing purposes. It makes a difference to the organism whether the mind functions well or ill. But in attributing this teleological value to the mind, we have demanded two things. Not only must there be an organ to function in a purposive way, but this functioning must be carried out as well as the given conditions make possible. Other things being equal, that functional adjustment will be the best one which is made with the least expenditure of energy.
This may sound like an effort to translate psychology into pseudo mechanics, but I think there is really no mystery. No one would deny, I fancy, that, other things being equal, that adjustment of the organism is the best which is least exhausting to it. Vital energy, whatever that may be or depend upon (and I do not wish to imply any unique 'vital force'), is finite in quantity, so that it makes a great deal of dift'erence whether our energy is wasted or not. But if we banish the concept of a 'vital force' and mean by force only what is meant in mechanics, and then undertake to give a psychophysical account of the way in which Maeh's 'Principle of Economy' works, remembering that the idea of mechanical force is due to the sense of effort and energy in experience, it seems not inappropriate to find the mechanical equivalent of the principle of economy in the principle of least resistance. Accordingly, an early essay by Avenarius is entitled, 'Philosophy as Conceiving the World according to the Principle of Least Resistance. '
It may perhaps be said that this is an attempt to describe science itself as the line of least resistance, whereas science means effort, the expenditure of force. How much less is the effort involved in being indifferent to scientific problems! The man who cares nothing for science is, other things being equal, more economical, as regards his energy, than the eager scientist. Science is not, this view would hold, the line of least resistance, but a line of very great resistance.
This objection is, however, not so well founded as it seems to be at first glance. We find ourselves with a large program of theoretical interests on our hands. These interests are more or less lively attitudes on our part. We find ourselves responding to what interests us. We can not put the problems aside and be indifferent to them; they haunt us, and demand our attention, I am speaking, of course, of the men who care for problems, of the men who have
- ↑ The Science of Mechanics,' translated from 2d ed., Chicago, 1893, p, 490.
