“It was said by Plato,” Polybius continues, “that human affairs would be well administered when philosophers should be kings, or kings philosophers. In the same manner I would say: that history would be well composed if those who are engaged in great affairs would undertake to write it; not in a slight and negligent manner, like some of the present age; but regarding such a work as one of the noblest and most necessary of their duties, and pursuing it with unremitted application, as the chief business of their lives; or if those, on the other hand, who attempt to write, would think it necessary also to be conversant in the practice of affairs. Till this shall happen, there will be no end of mistakes in history.” [Illustration: SCIPIO AND POLYBIUS (From an old print)] But while thus speaking for men of affairs, Polybius has in mind also philosophers, for he declares that it is impossible to make a clear judgment of the victorious or vanquished by a bare account of events. We must know, he says, the laws and customs of the people, and the passions and circumstances which prevail among them with regard to public and private ends. With regard to the Romans in particular, he hopes by due attention to these things to present such a picture that the people of his own age will be able to discern “whether they ought to shun or choose subjection to the Romans; and posterity to judge whether the Roman government was worthy of praise and imitation or should rather be rejected as vicious and blamable;” for in this, he believes, must consist the utility of his history for his own and future ages.