Came here to mention the same thing. It's one of the pillars of the whole Witcher saga, but most clearly it's visible in Sapkowski's short stories - The Lesser

Came here to mention the same thing. It's one of the pillars of the whole Witcher saga, but most clearly it's visible in Sapkowski's short stories - The Lesser Evil, A Grain of Truth, A Question of Price, The Witcher, to name just a few.