* In some remarkable passages of the Botany of Sir James Ross's
Antarctic voyage, which took place half a century ago, Sir
Joseph Hooker demonstrated the dependence of the animal life of
the sea upon the minute, indeed microscopic, plants which float
in it: a marvellous example of what may be done by
water-culture. One might indulge in dreams of cultivating and
improving diatoms, until the domesticated bore the same
relation to the wild forms, as cauliflowers to the primitive
Brassica oleracea, without passing beyond the limits of fair
scientific speculation.
That which is true of the purely pastoral condition is a fortiori true of the purely agricultural* condition, in which the existence of the cultivator is directly dependent on the production of vital capital by the plants which he cultivates. Here, again, the condition precedent of the work of each year is vital capital. Suppose that a man lives exclusively upon the plants which he cultivates. It is obvious that he must have food-stuffs to live upon, while he prepares the soil for sowing and throughout the period which elapses between this and harvest. These food-stuffs must be yielded by the stock remaining over from former crops. The result is the same as before—the pre-existence of vital capital is the necessary antecedent of labour. Moreover, the amount of labour which contributes, as an accessory condition, to the production
of the crop varies as widely in the case of plant-raising as in that of cattle-raising. With favourable soil, climate and other conditions, it may be very small, with unfavourable, very great, for the same revenue or yield of food-stuffs.
* It is a pity that we have no word that signifies plant-culture
exclusively. But for the present purpose I may restrict
agriculture to that sense.
Thus, I do not think it is possible to dispute the following proposition: the existence of any man, or of any number of men, whether organised into a polity or not, depends on the production of foodstuffs (that is, vital capital) readily accessible to man, either directly or indirectly, by plants. But it follows that the number of men who can exist, say for one year, on any given area of land, taken by itself, depends upon the quantity of food-stuffs produced by such plants growing on the area in one year. If a is that quantity, and b the minimum of food-stuffs required for each man, A/B=N, the maximum number of men who can exist on the area. Now the amount of production (a) is limited by the extent of area occupied; by the quantity of sunshine which falls upon the area; by the range and distribution of temperature; by the force of the winds; by the supply of water; by the composition and the physical characters of the soil; by animal and vegetable competitors and destroyers. The labour of man neither does, nor can, produce vital capital; all that it can do is to modify, favourably or unfavourably, the conditions of its production. The most important of these—
namely, sunshine, range of daily and nightly temperature, wind—are practically out of men's reach.* On the other hand, the supply of water, the physical and chemical qualities of the soil, and the influences of competitors and destroyers, can often, though by no means always, be largely affected by labour and skill. And there is no harm in calling the effect of such labour "production," if it is clearly understood that "production" in this sense is a very different thing from the "production" of food-stuffs by a plant.
* I do not forget electric lighting, greenhouses and hothouses,
and the various modes of affording shelter against violent
winds: but in regard to production of food-stuffs on the large
scale they may be neglected. Even if synthetic chemistry should
effect the construction of proteids, the Laboratory will
hardly enter into competition with the Farm within any time
which the present generation need trouble itself about.
We have been dealing hitherto with suppositions the materials of which are furnished by everyday experience, not with mere a priori assumptions. Our hypothetical solitary shepherd with his flock, or the solitary farmer with his grain field, are mere bits of such experience, cut out, as it were, for easy study. Still borrowing from daily experience, let us suppose that either sheep-owner or farmer, for any reason that may be imagined, desires the help of one or more other men; and that, in exchange for their labour, he offers so many sheep, or quarts of milk, or pounds of