Through The Looking Glass by Lewis Carroll Chapter 4 Page 20

‘Ditto, ditto’ cried Tweedledee.

He shouted this so loud that Alice couldn’t help saying, ‘Hush! You’ll be waking him, I’m afraid, if you make so much noise.’

‘Well, it no use your talking about waking him,’ said Tweedledum, ‘when you’re only one of the things in his dream. You know very well you’re not real.’

‘I am real!’ said Alice and began to cry.

‘You won’t make yourself a bit realler by crying,’ Tweedledee remarked: ‘there’s nothing to cry about.’

‘If I wasn’t real,’ Alice said — half-laughing through her tears, it all seemed so ridiculous —