If the general accounts of the battle of Murfreesboro, in the absence of special details, are to be relied upon, we should have had no victory but for the admirable leadership of Gen. ROSECRANS. He was the master-spirit of the occasion--discovering every exigency with eagle glance, and doing on the instant the right thing to meet it. Now rallying the wing broken by the overwhelming masses of the foe, and forthwith forming a new and firmer front -- now bringing up supports whenever his lines wavered -- now seizing the opportune moment to put himself in person at the head of his columns and charge home upon the enemy -- ever knowing just what to do, and ever flying to his mark, he was not only a chief, but he was everywhere an inspiration. Not only his mind directed, but his spirit fired. Probably not since this war began has a victory been wrested from the enemy by such plenitude of resource, and such unrelenting determination, on the part of the Commanding General, as was this. The rebels have seldom fought with such fury; never with such tenacity. They were handled by their Generals -- JOHNSON and BRAGG -- with consummate skill. They gave battle in their own chosen position, and with numbers certainly equaling, and probably much exceeding, our own forces. But nothing availed to save them from disastrous defeat.

Whatever his future may be, it cannot be denied that at the present moment Gen. ROSECRANS, if success be the standard, stands at the very head of the Union Generals. The discretion of the Government, in placing him in command of the second most important military department, is more than justified. ROSECRANS was in reality the real hero of the successes of Western Virginia, which did so much for MCCLELLAN in the early stages of the war. It was he alone who won the decisive battle of Rich Mountain or Laurel Hill, -- taking the intrenchments in the rear by cutting a new road of nine miles through the mountain forest, and precipitating himself upon the dismayed enemy, to their utter overthrow, before MCCLELLAN, in execution of his part of the plan, had got in front at all. The same success attended him, as Commander of the Department, after MCCLELLAN left. He cleared the country entirely of the enemy; though, with its ravines, and jungles, and by-roads, and blind paths, and mountain passes, there probably is not a district in the whole country presenting more difficulties for such operations. His driving back the greatly superior forces of WISE and FLOYD, ending with the complete rout of the latter from his stronghold at Carnifex Ferry -- which was done by ROSECRANS on the same day that he had marched seventeen miles over the roughest roads -- will ever stand among the brilliant exploits of the war. In the Valley of the Mississippi -- saying nothing of his twenty miles march and overthrow of PRICE at Iuka, all in a single day -- it was reserved for ROSECRANS to achieve the most decided and glorious land victory of the year, at Corinth, in spite of tremendous odds; and the splendid manner in which he followed that victory up with instantaneous pursuit and a second rout of the enemy at the Hatchie River, is fresh in the memory of all.

Why has Gen. ROSECRANS been so peculiarly successful? We are not yet prepared to attribute it to any superiority in natural genius, or in acquired science, or in personal energy over other commanders. As for genius, in the proper sense, we have yet to be satisfied that the gift exists at all among the chiefs either of our army or that of the rebels. In book science, ROSECRANS is doubtless exceeded both by MCCLELLAN and by BUELL. In energy, he is perhaps equaled by BURNSIDE and by GRANT. What, then, is his advantage? We believe it lies in his invariable practice of being personally present on the field of battle, where he sees for himself every movement, gives the appropriate command without delay, and, if necessary, takes an active part personally in the struggle. GRANT is the only other one of the chiefs in command who ever did this, and he only occasionally and imperfectly. BUELL never was within the sound of cannon, save at Shiloh. MCCLELLAN was at no time within two miles of the hot strife of a battle field, either in Western Virginia, or on the Peninsula; or in Maryland, save at Antietam, and there the deep creek flowed between him and the scene of action. So with BURNSIDE at Fredericksburgh. He not only kept himself on this side of the Rappahannock through the whole of that terrible day, but would not even permit Gen. SUMNER, his second in command, to cross over and put himself at the head of his corps.

ow, we are no West-Pointers, but we make bold to say that this is not the highest style of generalship. It sacrifices two most important concerns -- promptitude and personal inspiration. Every reader of military history knows that the fate of a battle often turns upon some immediate manoeuvering of the different grand divisions, consequent upon some unlooked-for event. None but the Chief is competent to issue the commands necessary for such movements. If he is not at hand to do it at once, the battle may be lost without remedy. BONAPARTE is believed to have had some experience in these matters; and he said that he had "observed that it was always the quarters of an hour that decide the fate of a battle." How then can it he right for any Commanding General before a battle to fix himself where at least. one quarter of an hour, and perhaps two or three, must be consumed in obtaining from him any new order? Again, in respect to personal prestige: if a General is what he should be, he has the confidence of his soldiers more than any other man in his army, and his presence is always encouraging and inspiring. Said BONAPARTE on another occasion: "In all battles a moment occurs when the bravest troops, after having made the greatest efforts, feel inclined to run. That terror proceeds from a want of confidence in their own courage; and it only requires a slight opportunity, a pretence, to restore confidence to them. You see that two armies are two bodies which meet, and endeavor to frighten each other; a moment of panic occurs, and that moment must be turned to advantage. When a man has been present in many actions, he distinguishes that moment without difficulty; it is as easy as casting up addition." And yet, easy and indispensable as BONAPARTE said it was, our chiefs have usually kept so far away that its performance is out of the question. In these critical instants, they have no chance whatever of exercising a personal influence upon their soldiers.

Perhaps these Commanding Generals and their friends may say that their presence on the battle-field, or in close proximity to it, would involve great personal exposure, and that their fall might derange the whole plan of the battle. We will concur in that view just so soon as it shall be proved that we have any General whose transcendant abilities render him more important to his army than NAPOLEON, and WELLINGTON, and FREDERICK the Great, and EUGENE, and CHARLES the Twelfth, were to theirs. We will cheerfully make a special exception of any such Commander, when he shall be found, and not ask that he should do as they did. But, as to others, we believe the cause will benefit rather than suffer by their keeping as near as practicable to the work they have in hand, even at a good deal of personal peril. ROSECRANS has now again shown the value of it, and there is not one of them who is not as brave as he.