Nor can doubt be thrown on these deeds by the fact that they are only mentioned by Quintus Curtius and not by Arrian. The silence of the one is no proof of the falsity or credulity of the other. Both writers lived many centuries after Alexander, and were dependent for their knowledge on the writings, then extant but long since lost, of contemporaries and eye-witnesses of the expedition to Asia. That those witnesses often gave conflicting accounts of the same event we have the assurance of either writer; but since it is impossible to determine the degree of discretion with which each made their selections from the original authorities, it is only reasonable to regard them both as of the same and equal validity. Seneca, who lived before Arrian and who therefore was equally conversant with the original authorities, hardly ever mentions Alexander without expressions of the strongest reprobation. Cruelty, in fact, is revealed to us by history as the most conspicuous trait in the character of Alexander, though not in his case nor in others inconsistent with occasional acts of magnanimity and the gleams of a higher nature. This cruelty, however, taken in connection with his undoubted bravery, calls in question the truth of a remark made by Philip de Commines, and supported, he affirmed, by all historians, that no cruel man is ever courageous. The popular theory, that inhumanity is more likely to be the concomitant of a timid than of a daring nature, ignores altogether the teaching of history and the conclusions of _à priori_ reasoning. For if our regard for the sufferings of others is proportioned to our regard for our own sufferings, inasmuch as our self-love is the foundation and measure of our powers of sympathy, a man’s disregard for the sufferings of others--in other words his cruelty--is likely to be the exact reflection of his disregard for suffering in his own person, or, in other words, of his physical courage. Men, moreover, like Cicero, of whom it was said by Livy that he was better calculated for anything than for war, by their very incapacity for positions where their humanity is likely to be tested, are rarely exposed to those temptations of cruelty in which men of a more daring temperament naturally find themselves placed.