Those discoveries, then, by altering the physical powers of men, by changing their relations and connections, as well as by opening new fields for commerce, and new channels for carrying it on, form a very distinct epoch in the history of wealth and power, and alter greatly their nature in the detail; though, in the main outline and abstract definition, they are still the same; having always the same relation to each other, or to the state of things at the time. This last period is then very different in its nature, and much more important than either of the others that preceded it; yet, in one thing, there is a similarity that runs through the whole, and it is a very important one. The passions and propensities of mankind, though they have changed their objects, and the means of their gratification, have not changed their nature. The desire of enjoyment; and of enjoyment with the least trouble possible, appears to be the basis of all the passions. Hence, envy, jealousy, friendship, and the endless train of second-rate effects, appear all to be produced by that primary passion; {9} and as from --- {9} The very learned and ingenious author of the Inquiry into the Origin and Causes of the Wealth of Nations, traces all this to an innate propensity to barter. But barter is only a means, and not even the means to which mankind shew the greatest pro-[end of page #5] pensity; for, wherever they have power to take by force or pillage, they never barter. This is seen both in an infantine and adult state; children cry for toys, and stretch at them before they offer to exchange; and, conquerors or soldiers never buy or barter, when they can take, unless they are guided by some other motive than mere natural propensity. A highwayman will pay for his dinner at an inn, as willingly as a traveller, because he acts from other motives than propensity, but he will strip the inn-keeper when he meets him on the road. -=- this originate the wealth as well as the decline of nations, the history of the revolutions in wealth and power, during the two first periods, are by no means unimportant; besides, as their duration was much longer than that of the latter, they lead to a more certain conclusion. The review of what has taken place will occupy the first book; and serve as a data for an inquiry into the nature and causes of the fall of nations. The first part of the second book will be dedicated to investigating the internal causes of decline; that is to say, all those causes which arise from the possession of wealth and power, operating on the habits, manners, and minds of the inhabitants; as also on the political arrangements, laws, government, and institutions, so far as they are connected with the prosperity or decline of nations.