200 THE SCIENCE OF LOGIC. 



be seen (i 18, 120) to be implied in the primary form, No non-S 

 is P, being &quot;immediate inferences &quot; (2) the inverse, and (3) the 

 obver ted converse from this primary form. 



(b~) The Exceptive Proposition is one which withholds the pre 

 dicate from some portion of the denotation of the subject, by such 

 words as &quot;except,&quot; &quot;unless,&quot; &quot;but&quot;. For example, &quot;All 

 members, except those over seventy years of age, are bound to be 

 present,&quot; &quot; All the passengers, but two, escaped uninjured,&quot; &quot; No 

 one is admitted, unless on business and by appointment &quot;. 



These examples will show that the exceptive and exclusive 

 propositions are merely two different ways of expressing the same 

 meaning, that the exceptive may always be changed into the ex 

 clusive by making the excepted portion the subject of the new pro 

 position, and changing the quality : the examples just given may 

 be expressed, &quot; Only members over seventy years of age are not 

 bound to be present,&quot; &quot; Two passengers alone did not escape un 

 injured,&quot; &quot; Only people who come on business and by appointment 

 are admitted&quot;. 



(c) Yet another form of exponible proposition is \ht Inceptive, 

 or the Desitive proposition, i.e. the proposition which asserts 

 something as beginning or ending. Such a proposition may be 

 resolved into two, the one showing the state of affairs before, the 

 other after, the change. For example, &quot;Dirigible airships came 

 into use during the first decade of the twentieth century &quot;. This 

 is equivalent to two propositions, one stating that such airships 

 were not in use previously, the other that they were in use sub 

 sequently, to the time referred to. 



96. INDESIGNATE PROPOSITIONS. If the subject of a pro 

 position is affected by any of the signs of quantity discussed in 

 the preceding paragraphs, there will be comparatively little 

 difficulty in determining whether the proposition is universal or 

 particular. But not all propositions in ordinary discourse have 

 signs of quantity attached to their subjects. A proposition which 

 contains no such sign to indicate its quantity is called an In- 

 designate Proposition. It might also be appropriately described 

 as Indefinite inasmuch as its quantity is left undefined ; were it 

 not that the term &quot; indefinite &quot; is often used as synonymous with 

 &quot; particular&quot;. Hence, we had better describe simply as indesig- 

 nate, propositions which have no sign of quantity expressed. 

 And in regard to these, we have to inquire how we are to de 

 termine their quantity whether they are universal or particular. 



