But if one premiss is assertoric, the other problematic, if the affirmative is assertoric and the negative problematic no
syllogism1 will be possible, whether the premisses are universal or particular. The proof is the same as above, and by means of the same terms. But when the affirmative premiss is problematic, and the negative assertoric, we shall have a syllogism. Suppose A belongs to no B, but can belong to all C. If the negative proposition is converted, B will belong to no A. But ex hypothesi can belong to all C: so a syllogism is made, proving by means of the first figure that B may belong to no C. Similarly also if the
minor2 premiss is negative. But if both premisses are negative, one being assertoric, the other problematic, nothing follows necessarily from these premisses as they stand, but if the problematic premiss is converted into its complementary affirmative a syllogism is formed to prove that B may belong to no C, as before: for we shall again have the first figure. But if both premisses are affirmative, no syllogism will be possible. This arrangement of terms is possible both when the relation is positive, e.g. health, animal, man, and when it is negative, e.g. health, horse, man.
The same will hold good if the syllogisms are particular. Whenever the affirmative proposition is assertoric, whether universal or particular, no syllogism is possible (this is proved similarly and by the same examples as above), but when the negative proposition is assertoric, a conclusion can be
drawn3 by means of
conversion4, as before. Again if both the relations are negative, and the assertoric proposition is universal, although no conclusion follows from the actual premisses, a syllogism can be obtained by converting the problematic premiss into its complementary affirmative as before. But if the negative proposition is assertoric, but particular, no syllogism is possible, whether the other premiss is affirmative or negative. Nor can a conclusion be drawn when both premisses are indefinite, whether affirmative or negative, or particular. The proof is the same and by the same terms.
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收听单词发音
1
syllogism
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n.演绎法,三段论法 |
参考例句: |
- The ramifications or the mystery of a syllogism can become a weariness and a bore.三段论证法的分歧或者神秘会变成一种无聊、一种麻烦。
- The unexpected bursts forth from the syllogism.三段论里常出岔子。
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2
minor
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adj.较小(少)的,较次要的;n.辅修学科;vi.辅修 |
参考例句: |
- The young actor was given a minor part in the new play.年轻的男演员在这出新戏里被分派担任一个小角色。
- I gave him a minor share of my wealth.我把小部分财产给了他。
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3
drawn
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v.拖,拉,拔出;adj.憔悴的,紧张的 |
参考例句: |
- All the characters in the story are drawn from life.故事中的所有人物都取材于生活。
- Her gaze was drawn irresistibly to the scene outside.她的目光禁不住被外面的风景所吸引。
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4
conversion
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n.转化,转换,转变 |
参考例句: |
- He underwent quite a conversion.他彻底变了。
- Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。
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