On July 20th, writing to Madame Ritschl, he expressed the thoughts which occupied his solitude. First he gave expression to a fear which, as it seemed, the memory of a Greece ruined by the conflict of Sparta and Athens inspired in him. "Unhappy, historical analogies teach us that the very traditions of culture may be destroyed by the bitterness of such a war of nations." But he also expressed the emotion which had begun to seize him. "How I am ashamed of this inactivity in which I am kept, now that the instant has come when I might be applying what I learned in the artillery. Naturally I make myself ready for an energetic course of action, in case things should take a bad turn; do you know that the students of Kiel have enlisted together, with enthusiasm?" On the morning of August 7th he read in his paper the dispatches from Wörth: _German victory: Enormous losses._ He could no longer remain in his retreat. He returned to Basle, asked and obtained from the Swiss authorities permission to serve in the ambulance corps, and proceeded at once to Germany to enlist for the war which allured him. He crossed conquered Alsace: he saw the charnel houses of Wissembourg and of Wörth: on August 29th he bivouacked not far from Strassburg, where conflagrations lit up the horizon; then he made his way, by Lunéville and Nancy, towards the country around Metz, now converted into an immense ambulance, where the wounded of Mars-la-Tour, Gravelotte and Saint-Privat, so numerous that it was difficult to nurse them, were dying of their wounds and of infectious illnesses. Some unfortunates were given into his charge: he did his duty with kindness and courage, but experienced a singular emotion, a sacred and almost enthusiastic horror. For the first time he considered without repulsion the labour of the masses. He watched those millions of beings, some struck down and marked by death, others marching the roads or standing under arms: he considered them without contempt, he esteemed their destiny. Under the menaces of war, these men have something momentous about them. They forget their vain thoughts; they march, they sing, they obey their chiefs; they die. Friedrich Nietzsche was recompensed for his pains; a fraternal impulse uplifted his soul, he no longer felt his solitude, he loved the simple people who surrounded him. "All my military passions awake," he writes, "and I cannot satisfy them! I would have been at Rezonville, at Sedan, actively, passively perhaps. This Swiss neutrality always ties my hands." His passage through France was rapid. He received orders to convey the wounded in his care to the hospital at Carlsruhe.