As long, for example, as water is taken to be just the thing which we directly expedience it to be, we can put it to afew direct uses, such as drinking, washing, etc. Beyond heating it there was little that could be done purposefully to change its properties. When, however, water is treated not as the glisten- ing, rippling object with the variety of qualities that delight the eye, ear, and palate, but as something symbolized by FLO, something from which these qualities are completely absent, it becomes amenable to all sorts of other modes of control and adapted to other uses. Similarly, when steam and ice are no longer treated as what they are in their qualitative differences from one another in direct experience, but as homogeneous molecules moving at measured velocities through specified dis- tances, differential qualities that were barriers to effective regu- lations, as long as they were taken as finalities, are done away with. Asingle way of acting with respect to them in spite of their differences is indicated. This mode of action is capable of extension to other bodies, in principle to any bodies irre- spective of qualitative differences of solid, liquid and gaseous, provided they are given alike mathematical formulation. Thus all sorts of modes of expansion and contraction, of re- frigeration and evaporation, of production and regulation of explosive power, become possible.