Chapter 19

In order to avoid having a syllogism¹ drawn² against us we must take care, whenever an opponent asks us to admit the reason without the conclusions, not to grant him the same term twice over in his premisses, since we know that a syllogism cannot be drawn without a middle term, and that term which is stated more than once is the middle. How we ought to watch the middle in reference to each conclusion, is evident from our knowing what kind of thesis is proved in each figure. This will not escape us since we know how we are maintaining the argument.

That which we urge men to beware of in their admissions, they ought in attack to try to conceal³. This will be possible first, if, instead of drawing the conclusions of preliminary syllogisms, they take the necessary premisses and leave the conclusions in the dark; secondly⁴ if instead of inviting⁵ assent⁶ to propositions which are closely connected they take as far as possible those that are not connected by middle terms. For example suppose that A is to be inferred to be true of F, B, C, D, and E being middle terms. One ought then to ask whether A belongs to B, and next whether D belongs to E, instead of asking whether B belongs to C; after that he may ask whether B belongs to C, and so on. If the syllogism is drawn through one middle term, he ought to begin with that: in this way he will most likely deceive his opponent.

1 syllogism   

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。

2 drawn   

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。

3 conceal   

v.隐藏，隐瞒，隐蔽

参考例句：

• He had to conceal his identity to escape the police.为了躲避警方，他只好隐瞒身份。
• He could hardly conceal his joy at his departure.他几乎掩饰不住临行时的喜悦。

4 secondly   

adv.第二，其次

参考例句：

• Secondly,use your own head and present your point of view.第二，动脑筋提出自己的见解。
• Secondly it is necessary to define the applied load.其次，需要确定所作用的载荷。

5 inviting   

adj.诱人的，引人注目的

参考例句：

• An inviting smell of coffee wafted into the room.一股诱人的咖啡香味飘进了房间。
• The kitchen smelled warm and inviting and blessedly familiar.这间厨房的味道温暖诱人，使人感到亲切温馨。

6 assent   

v.批准，认可；n.批准，认可

参考例句：

• I cannot assent to what you ask.我不能应允你的要求。
• The new bill passed by Parliament has received Royal Assent.议会所通过的新方案已获国王批准。