'Wizardry is knowledge,' Ingold said one afternoon as they sat on the white boulders that lined the bottom of an arroyo where they had taken shelter from the wind. The land was growing higher and less grassy, the waving fields of long brown grasses giving way to short bunchgrass and huge, scraggy-barked sagebrush. Dry washes cut the land, scattering it with stone and gravel. At the bottom of this one, a thin trickle of water ran, edged with ice even at high noon. It burned Rudy's fingers through his gloves as he filled the drinking bottles. Ingold sat on the rocks behind him, idly drawing the dry, yellowish blossoms of a dead stalk of kneestem through his fingers as he scanned, without seeming to, the banks of the gully against the pallid sky. 'Even the most talented adept is useless without knowledge, without the awareness of every separate facet of the world within which he must work.'

'Yeah,' Rudy said, sitting back and stoppering the flask with stiff, clumsy fingers. 'But a lot of what you've been teaching me sometimes seems kind of useless. Like that kneestem you've got - I mean, it doesn't have anything to do with magic. It's just a weed. You said yourself it's worthless.'

'It is worthless to us and to animals, having no value either as medicine or as food,' Ingold agreed, turning the dry wisp in his mittened fingers. 'But we ourselves are useless to other forms of life - except, I might point out, as sustenance to the Dark Ones. Kneestem, like you and me, exists for its own sake, and we must take that into account in all our dealings with the world that we hold in common with it.'

'I see your point,' Rudy said, after a moment's consideration of how much of what he loved and valued was, objectively, pretty useless. 'But I didn't know jack about anything when I started magic. I called fire because I had to.'

'No,' the wizard contradicted. 'You called fire because you knew it could be done.'