The knight of QB3 is under obligation, the moment the enemy gives him the chance, of undertaking an invasion of the center by Kn-Q5.
Aron NimzowitschHow vain are our fears! I thought to myself. Sometimes we fear that which our opponent (or fate) had never even considered! After this, then, is it any longer worthwhile to rack one's brain to find new ghosts to fear? No, indeed: All hail optimism! - upon playing Hermanis Mattison after he overlooked an unusual knight manouevre.
Aron NimzowitschThe chess world is obligated to organize a match between the champion of the world and the winner of this Carlsbad tournament - indeed, this is a moral obligation. If the world of chess should remain deaf to its obligation, on the other hand, it would amount to an absolutely unforgivable omission, carrying with it a heavy burden of guilt.
Aron Nimzowitsch