The Light Fantastic:
Overview
The Disc, being flat, has no real horizon. Any adventurous sailors who get funny ideas from staring at eggs and oranges for too long and set out for the antipodes soon learned that the reason why distant ships sometimes looked as though they were disappearing over the edge of the world was that they were disappearing over the edge of the world.
[p. 19]
If the laws of action and reaction had anything to do with it, it should have flopped to the ground a few feet away. But no-one was listening to them.
[p. 53]
'What shall we do?' said Twoflower.
'Panic?' said Rincewind hopefully.
[p. 61]
He felt that the darkness was full of unimaginable horrors - and the trouble with unimaginable horrors was that they were only too easy to imagine...
[p. 81]
He wasn't good or evil or cruel or extreme in any way but one, which was that he had elevated greyness to the status of a fine art and cultivated a mind that was as bleak and pitiless and logical as the slopes of Hell.
[p. 111]
'On whose authority?' demanded Wert. Trymon turned his grey eyes on him.
'Mine. I need no other.'
[p. 115]
It was the sort of grin people use when they stare at your left ear and tell you in an urgent tone of voice that they are being spied on by secret agents from the next galaxy. It was not a grin to inspire confidence. More horrible grins had probably been seen, but only on the sort of grinner that is orange with black stripes, has a long tail and hangs around in jungles looking for victims to grin at.
[p. 183]
THE DEATH OF A WARRIOR OR THE OLD MAN OR THE LITTLE CHILD, THIS I UNDERSTAND, AND I TAKE AWAY THE PAIN AND END THE SUFFERING. I DO NOT UNDERSTAND THIS DEATH-OF-THE-MIND.
[p. 196]
'Listen,' said Rincewind. 'It's all over, do you see? You can't put the spells back in the book, you can't unsay what's been said, you can't-'
'You can try!'
[p. 250]
(...) there were far worse things than Evil. All the demons in Hell would torture your very soul, but that was precisely because they valued souls very highly; Evil would always try to steal the universe, but at least it considered the universe worth stealing. But the grey world behind those empty eyes would trample and destroy without even according its victims the dignity of hatred. It wouldn't even notice them.
[p. 256]