Trade phenomena, to which this Lesson has been devoted, though they lead down to the Basic Facts, the foundation facts, of Economics, do not themselves, either wholly or in any of their details, belong in the Basic Fact region. Though nearer to the Basic Facts of Economics than the phenomena of Money, our consideration of which immediately preceded our consideration of Trade, the phenomena of Trade are one layer above the Basic Facts toward which we have been delving down from the Economic surface, Money, and through the subsurface, Trade. To the Basic Facts of Economics our next Lesson will be devoted. FOURTH LESSON THE BASIC FACTS The purpose of the preceding Lessons has been to pierce through the surface and the immediate subsurface of Economics down to the Basic Facts. On the surface, as we have seen, Economics appears to be the science of making Money, whereas Money is in fact only the medium and measure of Value in Trade. We have further seen that the immediate subsurface, Trade, consists apparently in exchanges of tangible commodities but essentially in interchanges of human service. We are now to inspect the Basic Facts. The Basic Facts of Economics consist of natural groupings or categories of all the myriads of minor facts with which the science of Economics is concerned. Of those categories there are exactly three. By no possibility can there be more; by no possibility can there be less. Natural law fixes the number. The first Basic Fact--not first in order of creation, but first in our perceptions of Economic necessity--is Man. Without Man, Economics could have neither incentive nor power, neither cause nor effect. The second Basic Fact is Natural Resources, without which Man could not exist. Natural Resources comprise the surface of our globe, together with all natural objects external to Man and in their natural condition, upon the surface, under the surface, and above the surface, including the air surrounding the surface. Through applications of the energies of the first to the offerings of the second, Artificial Objects are produced, and these constitute the third of the three. To one or another of those three natural categories every variety of detail that may be involved in any Economic problem must be assigned. Not so to assign those details to their appropriate categories is to invite confusion of thought and to risk arriving at false and socially dangerous conclusions. The Economic student who mixes such Natural Resources as building sites with such Artificial Objects as buildings, or natural deposits of minerals with mining machinery, or natural surfaces with railway roadbeds and tracks and equipment, or farming tracts with farm improvements, or human slaves with real estate or stocks of merchandize or factory mechanisms, makes an inexcusable blunder.