“Yes,” said Ed. “That’s how law originated, and civilization is simply a state of existence in which there are laws enough to restrain wrong. When the savage finds that he can’t defend himself single-handed against murder and robbery, he joins with other savages for that purpose. That makes a tribe. It must have rules to govern it, and they are laws. It is out of the tribal organization that all civilized society has grown, mainly by the making of better and better laws, or by the better and better enforcement of laws already made.” “Then are we all savages, restrained only by law from indulging in every sort of crime?” asked Phil. “I, for one, don’t feel myself to be in that condition of mind.” “By no means,” replied the elder boy. “We are the products of habit and heredity. We have lost most of our savage instincts by having restrained them through generations, just as cows and dogs have done. You see, it is a law of nature that parents are apt to transmit their own characteristics to their children. As one of the great scientific writers puts it, ‘the habit of one generation is the instinct of the next.’ If you want a dog to hunt with, you choose one whose ancestors have been in the habit of hunting, because you know that he has inherited the habit as an instinct. Yet the highest-bred setters, pointers, and fox hounds are all descended ultimately from a common ancestry of wild dogs, as fierce, probably, as any wolf ever was. They have been for many generations under law,--the law of man’s control,--and so they have not only lost their wildness, but have acquired new instincts, new capacities, and a new intelligence.” “I see,” said Phil, meditatively. “It is a long-continued course of timely spanking that has slowly changed us from savages into fellows able to run a flatboat and inclined to wear trousers.” “Ah, as to that,” said Irv, “we haven’t quite got rid of our savage instincts even yet. I for one am savagely hungry for some of that beef our Cincinnati friend sent on board, and I suspect the rest of the tribe are in the same condition.” CHAPTER XXI A WRESTLE WITH THE RIVER After the boat left Memphis it was necessary to proceed with a good deal of caution. A new flood had come down the river, bringing with it a dangerous drift of uprooted trees and the like. Moreover, in many places there were strong currents setting out from the natural river-bed into the overflowed regions on either side, and constant care was necessary to avoid being drawn into these. Memphis is built upon the high Chickasaw bluffs, but a little way farther down the river the country becomes low and flat, and in parts it grows steadily lower as it recedes from the river, so that at some distance inland the plantations and woodlands lie actually lower than the bed of the great river. It has been said, indeed, with a good deal of truth, that the Mississippi River runs along on the top of a ridge.