A marked trait of Sherman's military intellect was his accurate judgment of the force of his enemy, and his freedom from the common fault of overestimating the army opposed to him. In his correspondence with General Thomas in April, discussing the preparations for the campaign and the severe reduction of burdens to a scale which was "rather the limit of our aim than what we can really accomplish," he had occasion to acknowledge the receipt of information concerning the enemy which Thomas had collected. "I read the reports of your scouts with interest," he said, but added, "I usually prefer to make my estimate of the enemy from general reasoning rather than from the words of spies or deserters." [Footnote: Official Records, vol. xxxii. pt. iii. p. 323.] The remark is significant. Prior to the opening of a campaign, whilst affairs are quiet, pretty reliable information of an enemy's strength and positions may usually be got; but when the time of action comes, the very air is full of excitement, and the "secret service" is apt to be a machine for self-delusion. Precedent knowledge supplemented by actual contact with the enemy is the best reliance for a capable general. His own reasoning from trustworthy data at the earlier point of departure, is, with such aids, his best guide. He knows where his enemy must be and what his force ought to be, better than his spies, or the enemy's deserters who, by a common stratagem, may be really hostile spies stuffed with the disturbing information they are sent to reveal.