OVER A LONG and distinguished career, University of Chicago historian William McNeill, now 65, has produced some of the most original and provocative work in the field of European history. Where the tendency among younger scholars has been toward narrow specialization, McNeill has continued to investigate the currents and patterns of historical development that transcend centuries and civilizations. In The Rise of the West, which won the National Book Award in 1964, McNeill essayed to write nothing less than "a history of the human community," tracing the evolution of human society and the shifting balance in the relationship between Western and Eastern civilizations since the Paleolithic age. In Plagues and Peoples (1976), he examined the critical yet often overlooked influence of infectious diseases on human affairs, assessing the effect of plague on war, religion, politics, and society from ancient to modern times. In what may be his most ambitious effort to date, The Pursuit of Power, he explores the relationship between changing military technology and modes of warfare and socio-economic change--a relationship that is complex, symbiotic, and, according to McNeill, fundamental in shaping the course of human history.

McNeill's latest theme is not a new one. Lynn White Jr. devoted an entire chapter of Medieval Technology and Social Change to the origin of the stirrup and its transformation of warfare and society (introduced into Europe early in the 8th century A.D., the stirrup markedly improved the stability and hence the prowess of horsemen, making cavalry a formidable force and contributing, so the thesis goes, to the rise of feudalism and chivalric culture). Grade schoolers learn that gunpowder, first used in Europe sometime in the 14th century, demolished medieval fortresses and therefore the feudal system. But, as in Plagues and Peoples, a subject treated previously and admirably by Hans Zinsser in Rats, Lice and History, McNeill takes a familiar problem and recasts it with fresh hypotheses and intriguing new dimensions.

As early as 1800 B.C., McNeill notes, one can discern a correlation between the alteration of armaments and the transformation of society. The invention of a spoked wheel that was precisely rounded and dynamically balanced made possible a war chariot of unprecedented mobility and sturdiness, enabling a driver with a skilled archer beside him to wreak havoc through opposing infantry. Controlling the battlefield, charioteers eventally shared in the exercise of political power, so valuable were they to their overlords, and because chariotry was so expensive (given the cost of the vehicle and horses), an aristocratic warrior class shortly emerged.

Just as dramatically, however, the military--and social--balance shifted after 1200 B.C. as the result of yet another technological development: the invention of a new technique for making metal arms and armor relatively cheaply returned the advantage to massed infantrymen, as hordes of ordinary farmers and herdsmen could now outfit themselves with shields and helmets of iron and be protected against the charioteers' arrows. As warfare was democratized, so was society--until the invention of the stirrup restored the preeminence of the cavalry and installed in power a new feudal aristocracy. The introduction of gunpowder and a heavy crossbow that could knock an armored knight from his horse at 100 yards relegated the cavalryman again to a secondary role. And so the process went, with changes in weapon systems transforming the conditions of warfare and eventually society itself.

Were this the extent of McNeill's argument, his work would be interesting enough but not particularly profound or original. Where he breaks new ground is in his novel treatment of the flip side of this phenomenon-- the effect of changing demographic and socio-economic conditions on warfare and military organization. Marked population growth after 1750, says McNeill, created larger armies that were hard to control and supply under established methods. Traditional forms of command and communication--galloping aides-de- camp, shouted commands, and buglers--became inadequate as armies and battle fronts expanded, necessitating increasing resort to written orders, small-scale mapping, and a new divisional organization. To solve the supply problem, farsighted rulers such as Frederick the Great included road and waterway improvements in their strategic planning.

McNeill's central hypothesis--it dominates much of the book--is that with the commercialization of world society that began about 1000 A.D., first in China and then in Europe, market forces rather than the commands of rulers determined military activities and organization. Bankers and entrepreneurs underwrote voyages of exploration, which were undertaken as long as their financial prospects appeared good and investors could be enlisted. Thus the British Royal Navy in the 16th century was indistinguishable from a merchant marine; even the Spanish Armada in 1588, with few state- owned galleons, had more merchantmen than warships. European rulers who resisted the new market forces and continued to operate to "command" principles (taxing subjects heavily to pay for state-owned armed forces) found their most inventive and productive citizens, including their most efficient arms manufacturers, moving elsewhere. Phillip II's failure to recognize the superior capabilities of the Dutch burghers he forced to flee Antwerp and then revolt, McNeill suggests, was the key factor in Spain's demise.

In countries such as Italy and the Netherlands, where merchant oligarchs controlled the state, the "commercialization of violence" occurred naturally and without resistance from traditional command-oriented elements: "trade" and "raid" were one and the same. Elsewhere, however, competition between traditional "military power" and "money power" created serious strains. "On land," McNeill writes, "the mingling of mercenary and military motives never worked as smoothly as on the sea." Noblemen continued to play a leading role in European armies, and "their ideals of prowess and personal honor were fundamentally incompatible with the financial, logistical, and routine administrative aspects of military management." Clinging to old-fashioned values of courage and muscular prowess as demonstrated in hand-to-hand combat, army leaders resisted not only the new bureaucratic organization but even much of the new technology, such as the mobile field artillery introduced in the late 18th century, with its "cold-blooded mathematics" that could "kill soldiers impersonally" at a distance of more than half a mile.

Because Western Europe eventually surpassed China in effectively reconciling the old command structure with the new market economy, McNeill argues, it and not China achieved global preeminence. As the commercialization and then (after 1800) industrialization of war in Western Europe made possible the spectacular growth of both armies and private wealth, collaboration between the private and public sectors expanded until by the late 19th century there were already in place in England and Germany the imposing foundations of a giant military-industrial complex; according to one estimate, by 1913 one-sixth of the entire male work force of Great Britain was dependent on naval contracting. In the 20th century, McNeill concludes on an ironic note, the increasing amalgamation of armament companies and collusion between business and government has resulted in effect in a return to "command" organization, as the huge costs of new weapon systems has made it too risky for either entrepreneurs or military planners to rely on the vagaries of the marketplace.

No summary can do justice to McNeill's intricate, encyclopedic treatment. There are long sections on the impact of the Thirty Years' War on military organization, the relationship between population growth and the French and industrial revolutions, and the psychological effects of the 17th-century innovation of close-order drill, which, McNeill contends, inculcated strong group sentiments and esprit de corps in an age of impersonal market relations. McNeill's erudition is stunning, as he moves easily from European to Chinese and Islamic cultures and from military and technological to socio-economic and political developments. The result is a grand synthesis of sweeping proportions and interdisciplinary character that tells us almost as much about the history of butter as the history of guns.

For all of the merits of this brilliant volume, there are the usual tradeoffs that accompany most McNeill works. McNeill's discursive style can become disjointed at times, or simply ponderous. Also, belonging to an older historiographical school of philosopher-humanists who emphasize the commonality of cultures and the universality of human dilemmas, McNeill sometimes makes too facile generalizations: he probably claims too much here for the conscious application of market principles in military decision-making after 1000 A.D. On balance, however, The Pursuit of Power is a compelling inquiry. McNeill's larger accomplishment is to remind us that all humankind has a shared past and, particularly with regard to its choice of weapons and warfare, a shared stake in the future.