They killed because they felt like killing, and yielded to the impulse, whatever its immediate origin. This conclusion is abundantly supported by the figures of the 'Chicago Tribune' for the seven years ending in 1900, when carefully analyzed. During this period 62,812 homicides were recorded. Of these there were 17,120 of which the causes were unknown and 3,204 committed while making a justifiable arrest, in self-defence, or by the insane, so that there were in fact only 42,488 felonious homicides the causes of which can be definitely alleged. The ratio of the "quarrels" to this net total is about seventy-five per cent. There were, in addition, 2,848 homicides due to liquor--that is, without cause. Thus eighty per cent of all the murders and manslaughters in the United States for a period of seven years were for no reason at all or from mere anger or habit, arising out of causes often of the most trifling character. Nor are the conclusions changed by the figures of the years between 1904 and 1909. During this period 61,786 homicides were recorded. Of these there were 9,302 of which the causes were not known, and 2,480 committed while making a justifiable arrest, in self-defence, or by the insane, leaving 50,004 cases of felonious homicides of known causes. Of these homicides, 33,476 were due to quarrels and 4,799 to liquor, a total of 38,275 out of the 50,004 cases of known causes being traceable in this, another seven years, to motives the most casual. It would be stupid to allege that the reason men killed was because they had been stepped on or had been deprived of a glass of beer. The cause lies deeper than that. It rests in the willingness or desire of the murderer to kill at all. Among barbaric or savage peoples this is natural; but among civilized nations it is hardly to be anticipated. If the negro who shoots his fellow because he believes himself to have been cheated out of ten cents were really civilized, he would either not have the impulse to kill or, having the impulse to kill, would have sufficient power of self-control to refrain from doing so. This power of self-control may be natural or acquired, and it may or may not be possessed by the man who feels a desire to commit a homicide. The fact to be observed--the interesting and, broadly speaking, the astonishing fact--is that among a people like ourselves anybody should have a desire to kill. It is even more astonishing than that the impulse should be yielded to so often if it comes.