Book I chapter 33

Men are frequently deceived about syllogisms because the inference is necessary, as has been said above; sometimes they are deceived by the similarity in the positing² of the terms; and this ought not to escape our notice. E.g. if A is stated of B, and B of C: it would seem that a syllogism¹ is possible since the terms stand thus: but nothing necessary results, nor does a syllogism. Let A represent the term ‘being eternal’, B ‘Aristomenes as an object of thought’, C ‘Aristomenes’. It is true then that A belongs to B. For Aristomenes as an object of thought is eternal. But B also belongs to C: for Aristomenes is Aristomenes as an object of thought. But A does not belong to C: for Aristomenes is perishable³. For no syllogism was made although the terms stood thus: that required that the premiss AB should be stated universally. But this is false, that every Aristomenes who is an object of thought is eternal, since Aristomenes is perishable. Again let C stand for ‘Miccalus’, B for ‘musical Miccalus’, A for ‘perishing to-morrow’. It is true to predicate B of C: for Miccalus is musical Miccalus. Also A can be predicated of B: for musical Miccalus might perish to-morrow. But to state A of C is false at any rate. This argument then is identical with the former; for it is not true universally that musical Miccalus perishes to-morrow: but unless this is assumed, no syllogism (as we have shown) is possible.

This deception⁴ then arises through ignoring a small distinction. For if we accept the conclusion as though it made no difference whether we said ‘This belong to that’ or ‘This belongs to all of that’.

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 positing   

v.假定，设想，假设( posit的现在分词 )

参考例句：

• Involves a contrast-a positing of walks that are opposites. 给我们看见强烈的对照﹕两种完全相反的生活样式。 来自互联网
• Global Positing System (GPS) technology has been widely used in many field. 全球定位系统(GPS)技术已经在许多领域得到广泛的应用。 来自互联网

3 perishable   

adj.（尤指食物）易腐的，易坏的

参考例句：

• Many fresh foods are highly perishable.许多新鲜食物都极易腐败。
• Fruits are perishable in transit.水果在运送时容易腐烂。

4 deception   

n.欺骗，欺诈；骗局，诡计

参考例句：

• He admitted conspiring to obtain property by deception.他承认曾与人合谋骗取财产。
• He was jailed for two years for fraud and deception.他因为诈骗和欺诈入狱服刑两年。