And indeed, after two days of searching the horizon in vain, on the third day Aragorn spied Gandalf astride a white horse cast in a pearly glow, leading the Riders of Rohan down upon the orcish rear, peeling them away from the seige and destroying them.
Now, Tolkien was a scholar of the era and so could not have been ignorant of a certain passage in Gregory of Tour's History of the Franks.
And Attila king of the Huns went forth from Metz and when he had crushed many cities of the Gauls he attacked Orleans and strove to take it by the mighty hammering of battering rams. Now at that time the most blessed Annianus was bishop in the city just mentioned, a man of unequaled wisdom and praiseworthy holiness, whose miracles are faithfully remembered among us. And when the people, on being shut in, cried to their bishop, and asked what they were to do, trusting in God he advised all to prostrate themselves in prayer, and with tears to implore the ever present aid of God in their necessities. Then when they prayed as he had directed, the bishop said: "Look from the wall of the city to see whether God's mercy yet comes to your aid." For he hoped that by God's mercy Ætius was coming, to whom he had recourse before at Arles when he was anxious about the future. But when they looked from the wall, they saw no one. And he said: "Pray faithfully, for God will free you this day." When they had prayed he said: "Look again." And when they looked they saw no one to bring aid. He said to them a third time: "If you pray faithfully, God comes swiftly." And they besought God's mercy with weeping and loud cries. When this prayer also was finished they looked from the wall a third time at the old man's command, and saw afar off a cloud as it were arising from the earth. When they reported this the bishop said: "It is the aid of the Lord." Meanwhile, when the walls were now trembling from the hammering of the rams and were just about to fall, behold, Ætius came, and Theodore, king of the Goths and Thorismodus his son hastened to the city with their armies, and drove the enemy forth and defeated him. And so the city was freed by the intercession of the blessed bishop, and they put Attila to flight.
-- Gregory of Tours, History of the Franks, Book II, ch. 7.
(And a thousand years later, the watchers on the walls of Orleans saw the Maid appear to relieve the long English seige.)
Then out spoke brave Horatius, the Captain of the Gate:
"To every man upon this earth, death cometh soon or late;
And how can man die better than facing fearful odds,
For the ashes of his fathers, and the temples of his Gods,
Speaking of fearful odds, Lars Porsena of Clusium had a considerable army to take Rome, but the three heroes held the narrow way before the bridge as it was chopped down behind them. Modern scholars, unable to imagine such people as Horatio or Joan or the rest, like to downplay these things or denigrate them or even suppose they could not have happened. But such words ring hollow from the lips of men to whom no statues will ever be raised.
Then too no one says that the fight must be a physical one, either. There are other walls to defend; other bridges to hold. One thinks of Guy de Chauliac in the Black Death meticulously recording the progression of the plague that ravaged his body; or Jesse Lazear allowing yellow fever mosquitoes to bite him. They had hope that their research would save others.
A few years ago TOF happened to hear on the radio an opinion-monger named Limbaugh deride the virtue of Hope, which he seemed to confuse with a sort of wishy-washfulness rather than the muscular Christian virtue. Vir-tue comes from vir, which gives us vir-ile and other strong words, which is why virtus translates as "strength." Hope is why you keep on fighting and you don't sit down and weep and wish that someone will come and make things right. Someone may come, like Gandalf or Aetius or the Maid, but to no good purpose if you haven't held on until then. And that is why the situation is not hopeless; because if there were no Hope, there would be no reason to go down fighting rather than to go down running. To paraphrase Chesterton, any fool can hope when success lies in view. It takes genuine strength to hope when matters seem hopeless. And that is why Hope is the mother of Courage. And Courage, as often as not, the mother of Joy.
“You must not lose hope,” said Joachim.
The Kratzer turned his great yellow eyes on the monk. “Hope! One of your ‘inner words.’ I know what you signify by ‘swine’ or ‘palfrey’ or ‘schloss,’ but what is ‘hope’?”
“When all else is lost,” Joachim told him, “it is the one thing you may keep.”