Since we know when a syllogism can be formed and how its terms must be related, it is clear when refutation will be possible and when impossible. A refutation is possible whether everything is conceded, or the answers alternate (one, I mean, being affirmative, the other negative). For as has been shown a syllogism is possible whether the terms are related in affirmative propositions or one proposition is affirmative, the other negative: consequently, if what is laid down is contrary to the conclusion, a refutation must take place: for a refutation is a syllogism which establishes the contradictory. But if nothing is conceded, a refutation is impossible: for no syllogism is possible (as we saw) when all the terms are negative: therefore no refutation is possible. For if a refutation were possible, a syllogism must be possible; although if a syllogism is possible it does not follow that a refutation is possible. Similarly refutation is not possible if nothing is conceded universally: since the fields of refutation and syllogism are defined in the same way.
同类推荐
Perils of Certain English Prisoners
本书为公版书，为不受著作权法限制的作家、艺术家及其它人士发布的作品，供广大读者阅读交流。汇聚授权电子版权。
热门推荐
破解失眠
快节奏高压力的生活使不少人的睡眠出了问题。本书希望帮助那些意识到睡眠有问题并希望改善的人群。书中列有五十条简洁有效可操作的方法，摒弃长篇大论，只求今夜入睡，明起赚钱。——作者约翰尼·罗斯是克里登城市科技协会创始人，这个协会云集六千多名伦敦精英，包括创业基金人、风投家、软件开发和创意人员等，立志要打造“伦敦南部的硅谷”。
