To such influences man is a passive subject, especially in the earlier stages of his development; but there are more important influences emanating from his environment which affect him as an active agent, challenge his will by furnishing the motives for its exercise, give purpose to his activities, and determine the direction which they shall take.[73] These mold his mind and character through the media of his economic and social life, and produce effects none the less important because they are secondary. About these anthropo-geography can reach surer conclusions than regarding direct psychical effects, because it can trace their mode of operation as well as define the result. Direct psychical effects are more matters of conjecture, whose causation is asserted rather than proved. They seem to float in the air, detached from the solid ground under foot, and are therefore subject matter for the psychologist rather than the geographer. [Sidenote: The great man in history.] What of the great man in this geographical interpretation of history? It seems to take no account of him, or to put him into the melting-pot with the masses. Both are to some extent true. As a science, anthropo-geography can deal only with large averages, and these exclude or minimize the exceptional individual. Moreover, geographic conditions which give this or that bent to a nation's purposes and determine its aggregate activities have a similar effect upon the individual; but he may institute a far-seeing policy, to whose wisdom only gradually is the people awakened. The acts of the great man are rarely arbitrary or artificial; he accelerates or retards the normal course of development, but cannot turn it counter to the channels of natural conditions. As a rule he is a product of the same forces that made his people. He moves with them and is followed by them under a common impulse. Daniel Boone, that picturesque figure leading the van of the westward movement over the Allegheny Mountains, was born of his frontier environment and found a multitude of his kind in that region of backwoods farms to follow him into the wilderness. Thomas Jefferson of Virginia, in the Louisiana Purchase, carried out the policy of expansion adumbrated in Governor Spottswood's expedition with the Knights of the Golden Horseshoe over the Blue Ridge in 1712. Jefferson's daring consummation of the purchase without government authority showed his community of purpose with the majority of the people. Peter the Great's location of his capital at St. Petersburg, usually stigmatized as the act of a despot, was made in response to natural conditions offering access to the Baltic nations, just as certainly as ten centuries before similar conditions and identical advantages led the early Russian merchants to build up a town at nearby Novgorod, in easy water connection with the Baltic commerce.[74] [Sidenote: Economic and social effects.]