384 LAW AND FREEDOM IN HISTORY

because it was, and always had been, believed by all denizens of the Old
World to be an unharvested and unharvestable sea, setting an impassable
physical western limit to the habitable portion of the Earth's surface. In
the fifteenth century of the Christian Era the Atlantic was challenging
the beleaguered peoples of Western Christendom by confronting them
with a choice between two extreme alternatives. If they were not to be
driven into the Atlantic in their turn, as they themselves had been
driving the hapless Celtic Christians, they must convert Seneca's fancy1
into fact by conquering an Ocean which not even a poet had ever
seriously supposed to be conquerable by Man 'in real life'. The dual
alarum of simultaneous challenges from the Atlantic and the 'Osmanli
was the emergency that, within the half century A J>. 1440-90, stimulated
Western shipwrights to create an Ocean-faring, globe-encircling sailing-
ship, capable of keeping the sea continuously for months on end, of
which the like had never before been designed or even imagined.

Why was this fifteenth-century outburst of creative energy in the
Western shipwright's trade followed by a spell of relative stagnation
lasting some three or four hundred years ? Challenge-and-Response is
the clue to the answer to this question likewise; for the creation of the
Modern Western ship had been so effective a response to the military
and political challenge presented to the West in the fifteenth century
that the fifteenth-century Western shipwright's epigoni had little in-
centive for seeking to improve on their predecessors' work until they
were eventually shaken out of their lethargy by a new challenge that was
not military or political but was economic, and that did not impinge on
the Western World from abroad but emerged from within.

The Modern Western ship had been an adequate solution for the
Early Modern Western World's besetting problem of Lebensraum. It
had enabled the Western peoples with one hand to acquire in the
Americas what looked like an inexhaustible addition to their reserves of
cultivable land, and with the other hand to seize for themselves a mono-
poly of all the existing Oceanic maritime trade in the World; and this
sudden turning of the tables in their favour in their competition with
the other living civilizations had not only given the Western peoples
full military and political security; it had also amply satisfied their
economic needs in an age in which they, as well as their contemporaries,
were still living under the traditional economic dispensation of Man in
Process of Civilization. In this dispensation—which, in the Lower Nile
Valley and the Lower Tigris-Euphrates Basin, had already been a going
concern at least as early as the end of the fourth millennium B.C.—
agriculture was the staple source of livelihood and the standard occupa-
tion, while trade and manufacture were subsidiary and exceptional. In
societies of this traditional type, towns and ports that lived by importing
foodstuffs and raw materials and paying for these by exporting manu-
factured goods and by performing the economic services of providing
and financing maritime and overland transportation, were few and far
between; rarer still were the parasitic capitals of oecumenical empires—
a Rome, a Constantinople, or a Peking—which used the lever of political

1 See Seneca: Medea, 11. 364—79, quoted in II. i. 263, n. i.