hari seldon remained uncomfortably silent for a while after hummins quiet statement. he shrank within himself in sudden recognition of his own deficiencies.

he had invented a new science: psychohistory. he had extended the laws of probability in a very subtle manner to take into account new complexities and uncertainties and had ended up with elegant equations in innumerable unknowns.

possibly an infinite number; he couldnt tell.

but it was a mathematical game and nothing more. he had psychohistory--or at least the basis of psychohistory but only as a mathematical curiosity. where was the historical knowledge that could perhaps give some meaning to the empty equations?

he had none. he had never been interested in history. he knew the outline of heliconian history. courses in that small fragment of the human story had, of course, been compulsory in the heliconian schools. but what was there beyond that? surely what else he had picked up was merely the bare skeletons that everyone gathered--half legend, the other half surely distorted. still, how could one say that the galactic empire was dying? it had existed for ten thousand years as an accepted empire and even before that, trantor, as the capital of the dominating kingdom, had held what was a virtual empire for two thousand years. the empire had survived the early centuries when whole sections of the galaxy would now and then refuse to accept the end of their local independence. it had survived the vicissitudes that went with the occasional rebellions, the dynastic wars, some serious periods of breakdown. most worlds had scarcely been troubled by such things and trantor itself had grown steadily until it was the worldwide human habitation that now called itself the eternal world.

to be sure, in the last four centuries, turmoil had increased somehow and there had been a rash of imperial assassinations and takeovers. but even that was calming down and right now the galaxy was as quiet as it had ever been. under cleon i and before him under his father, stanel vi, the worlds were prosperous--and cleon himself was not considered a tyrant. even those who disliked the imperium as an institution rarely had anything truly bad to say about cleon, much as they might inveigh against eto demerzel. why, then, should hummin say that the galactic empire was dying--and with such conviction?

hummin was a journalist. he probably knew galactic history in some detail and he had to understand the current situation in great detail. was it this that supplied him with the knowledge that lay behind his statement? in that case, just what was the knowledge?

several times seldon was on the point of asking, of demanding an answer, but there was something in hummins solemn face that stopped him. and there was something in his own ingrained belief that the galactic empire was a given, an axiom, the foundation stone on which all argument rested that prevented him too. after all, if that was wrong, he didnt want to know. no, he couldnt believe that he was wrong. the galactic empire could no more come to an end than the universe itself could. or, if the universe did end, then--and only then--would the empire end.

seldon closed his eyes, attempting to sleep but, of course, he could not. would he have to study the history of the universe in order to advance his theory of psychohistory?

how could he? twenty-five million worlds existed, each with its own endlessly complex history. how could he study all that? there were book-films in many volumes, he knew, that dealt with galactic history. he had even skimmed one once for some now-forgotten reason and had found it too dull to view even halfway through.

the book-films had dealt with important worlds. with some, it dealt through all or almost all their history; with others, only as they gained importance for a time and only till they faded away. he remembered having looked up helicon in the index and having found only one citation. he had punched the keys that would turn up that citation and found helicon included in a listing of worlds which, on one occasion, had temporarily lined up behind a certain claimant to the imperial throne who had failed to make good his claim. helicon had escaped retribution on that occasion, probably because it was not even sufficiently important to be punished.

what good was such a history? surely, psychohistory would have to take into account the actions and reactions and interactions of each world--each and every world. how could one study the history of twenty-five million worlds and consider all their possible interactions? it would surely be an impossible task and this was just one more reinforcement of the general conclusion that psychohistory was of theoretical interest but could never be put to any practical use. seldon felt a gentle push forward and decided that the air-taxi must be decelerating.

"whats up?" he asked.

"i think weve come far enough," said hummin, "to risk a small stopover for a bite to eat, a glass of something or other, and a visit to a washroom."

and, in the course of the next fifteen minutes, during which the air-taxi slowed steadily, they came to a lighted recess. the taxi swerved inward and found a parking spot among five or six other vehicles.