***
The learning of letters began the next day, as the tutor had promised. It was easy to see how the symbol could stand for the sound; easy, too, to draw the letters with his stylus in the soft wax. But it was less easy to remember which letter was which. He muddled them sometimes; alpha and gamma were the same forked figure turned on one side, and lambda was a gamma upside down, and then there were sigma and ksi which were just serpentine squiggles and he could never quite tell apart.
Then there were two o's, and two e's, and he could never remember which was which. His tutor, normally placid, began to show evidence of temper.
“Omega, not omicron, boy!” he yelled, one day, and Aranthur thought for a moment he was going to throw the tablet and stylus at the wall. Instead he turned suddenly on his heel, his breath hissing out in a violent sigh. Aranthur struggled on, his head bent over his work to disguise the hot shameful tears that were pooling on his eyelashes.
Philosophy, though, he loved; he felt as if he were exploring the unused lumber rooms of his own mind. Huge vistas opened before him, as if he'd been living besides some great precipice all this time, and only now looked over, and seen the virgin plains spread out below, the rivers and valleys that led to the sea, the dizzying height of the air and the depth of the gorge. Infinite worlds were the least of it.
“How do you know that I am the same tutor who taught you yesterday?”
He had no answer for that; it seemed obvious, but he'd soon learned that what seemed obvious was anything but.
“I have changed. Look; I tore this nail on my chiton this morning when I put it on. My beard has grown as I slept. I am a day older than I was yesterday. So I am not the same person.”
“But you are, obviously.”
“In what way?”
“You have the same memories, the same thoughts.”
“Ah. But I have new memories too. Like how the fingernail I caught in my chiton hurt. Or how you just answered my question.”
“Is this something else to do with infinite worlds?”
The tutor's eyes narrowed, and he leaned his head forward on his skinny neck. “In what way?”
Aranthur realised he'd said something that surprised the tutor; interested him, maybe.
“Well, there's you-yesterday, and you-today, and you-tomorrow, and so there is an infinite number of possible tutors.”
“Not infinite, not quite. Not in this world, anyway. But it's an interesting way of thinking about it. Anyway” - he had the air of someone desperately trying to get back to the road he'd been on - “change and continuity. What would make me a different person? Or to take another example, you step in a river. A year later you come back and cross the river again. Is it the same?”
“Of course not.”
“Explain.”
“The river flows to the sea. So the water is always different.” He smiled, thinking there, see, I've showed you what I've learned.
“No. The river is the same, isn't it? It has the same name, it flows in the same bed.”
Aranthur was crestfallen. He'd been certain he had the answer. And now it had receded again, that tenuous understanding, and his mind felt heavy and confused. Even so, he treasured the memory of that moment when he'd seen a glint of interest in his tutor's eyes.