With all these interesting contributions, there was also much in the way of devout star-gazing, with a consequent introduction of factors such as “natural-bounty,” “natural-forces” and “social-products,” which to the engineer appear too metaphysical to be used to vindicate the claim that economics is a science. In addition to all these, through thick and thin, there has been the disposition already noted to dwell upon the importance of capital. Capital is an important product of economic forces but not a primary factor. This cannot be too strongly emphasized.
Now, out of all these contributions to our list of primary factors, which can be measured? Obviously, only land-area with a foot-rule, population by a census and time by a chronometer. With this list of basic factors which can be calibrated, economics begins to look distinctly interesting to the engineer, who was apt to grow a little melancholy under the purely comparative approximations of psychology and metaphysics.
We must remember that we are sitting outside in the sun and have withheld judgment for the moment as to the value of the ancient formulæ. We are dealing with superficial speculations which claim the rank of science; but we have found that all just appraisement is halted by the lack of a logical unit of value.
Let us now try to get a clear picture of the economic field. The simplest conception is that of a closed vessel with two main ports or valves: first, that of birth or ingress, with an intermediate pressure-chamber or lock, walled off by humanity for tender youth, and second, that of death or egress, approached by its own intermediate pressure-chamber of old age. All that enters or leaves this main high-pressure area is the spirit, that human unit of energy with its normal positive rotation, quick or sluggish as the case may be, but driven ever by its need of physical freedom and lured by its inducement to amplify that freedom. This unit may be expressed by Figure 1, as a miniature organism always revolving and always tending to expand by centrifugal force (see page 53).
The whole economic zone itself, with its fixed base of land