Logical extreme

A logical extreme is a useful, though often fallacious, rhetorical device for the disputation of propositions. Quite simply, a logical extreme is the relevant statement of an extreme or even preposterous position that is nonetheless consistent with the proposition in question. Thus, in so far as the logically extreme position is both relevant and untenable, it has succeeded in calling the proposition into question, at least in its stated form. An example is in Basil Liddell Hart's essay 'Armed Forces and the Art of War: Armies' in The New Cambridge Modern History:

The worst effect of Clausewitz's views came through his metaphysical exposition of the idea of 'absolute' warfare. By taking the logical extreme as the theoretical ideal, he conveyed the impression, to superficial readers, that the road to success was through the unlimited application of force. [...] Moreover, Clausewitz contributed to the subsequent decay of generalship when in an oft-quoted passage he wrote--'Philanthropists may easily imagine that there is a skilful method of disarming and overcoming the enemy without great bloodshed, and that this is the proper tendency of the Art of War....It is an error which must be extirpated.' [...] Unfortunately Clausewitz's corrective arguments would henceforth be cited by countless blunderers to excuse, and even to justify, their futile squandering of life in bull-headed assaults.[1]

— J.P.T. Bury (ed), The New Cambridge Modern History, Book X: The Zemith of European: 1830-70