values and customs that were occurring at home. Newcomers would continue to arrive from the mother country, bringing with them new attitudes and life-styles that permeated the societies in which they took up residence. Equally, books and luxury items imported from Europe would introduce new ideas and tastes. News, too, circulated with growing speed and frequency around an Atlantic world that was shrinking as communications improved.
Similarly, changing ideas and priorities at the centre of empire were reflected in changes in imperial policy, so that the third or fourth generation of settlers might well find itself operating within an imperial framework in which the assumptions and responses of the founding fathers had lost much of their former relevance. This in turn forced changes. There were obvious continuities between the America of the first English settlers and the British America of the mideighteenth century, but there were important discontinuities as well - discontinuities brought about by external and internal change alike. The `immobilities of fragmentation' detected by Louis Hartz were therefore relative at best. British and Spanish America, as the two units of comparison, did not remain static but changed over time.
It still remains plausible, however, that the moment of 'fragmentation'- of the founding of a colony - constituted a defining moment for the self-imagining, and consequently for the emerging character, of these overseas societies. Yet, if so, there are obvious difficulties in comparing communities founded at very different historical moments. Spain's first colonies in America were effectively established in the opening decades of the sixteenth century; England's in the opening decades of the seventeenth. The profound changes that occurred in European civilization with the coming of the Reformation inevitably had an impact not only on the metropolitan societies but also on colonizing policies and the colonizing process itself. A British colonization of North America undertaken at the same time as Spain's colonization of Central and South America would have been very different in character from the kind of colonization that occurred after a century that saw the establishment of Protestantism as the official faith in England, a notable reinforcement of the place of parliament in English national life, and changing European ideas about the proper ordering of states and their economies.
The effect of this time-lag is to inject a further complication into any process of comparison which seeks to assess the relative weight of nature and nurture in the development of British and Spanish territories overseas. The Spaniards were the pioneers in the settlement of America, and the English, arriving later, had the Spanish example before their eyes. While they might, or might not, avoid the mistakes made by the Spaniards, they were at least in a position to formulate their policies and procedures in the light of Spanish experience, and adjust them accordingly. The comparison, therefore, is not between two self-contained cultural worlds, but between cultural worlds that were well aware of each other's presence, and were not above borrowing each other's ideas when this suited their needs. If Spanish ideas of empire influenced the English in the sixteenth century, the Spaniards repaid the compliment by attempting to adopt British notions of empire in the eighteenth. Similar processes, too, could occur in the colonial societies themselves. Without the example of the British colonies before them, would the Spanish colonies have thought the previously unthinkable and declared their independence in the early nineteenth century?
When account is taken of all the variables introduced by place, time, and the effects of mutual interaction, any sustained comparison of the colonial worlds of Britain and Spain in America is bound to be imperfect. The movements involved in writing comparative history are not unlike those