4 o8 SCIENCE PROGRESS 



the Alps, the convention of Logic requires us to suppose that 

 we do not " (p. 215). 



To the " traditional " logician it is clear that the middle term 

 is distributed in both premisses, for " The part of the Alps " 

 refers to the whole of that part, and so too does " the Alps " in 

 the first premiss. 



(4) Argument in which the middle term appears in the 

 conclusion : 



If Cherries will grow on calcareous soil, 

 and Rhododendrons will not grow on calcareous soil ; 

 then Calcareous soil is not equally suitable for all plants. 



This argument is not expressed in strictly syllogistic form, since 

 the syllogism requires a movement of thought which consists in 

 eliminating the middle term in order to bring out the connection 

 between the two extreme terms. In the given argument the 

 advance consists in the fact that soil suitable for cherries is seen 

 not to be suitable for rhododendrons. It can be expressed in 

 the form : 



Calcareous soil is suitable soil for cherries, 

 Calcareous soil is not suitable soil for rhododendrons ; 

 Therefore Soil suitable for cherries is not soil suitable for rhododendrons, 



and it is this conclusion which brings out the force of the 

 argument. 



(5) Argument with a term distributed in the conclusion, but 

 not in either of the premisses : 



If Some of the crew manned the jolly boat, 

 and Others of the crew manned the long boat ; 

 then The whole of the crew were enough to man both these boats. 



This argument is clearly not stated in syllogistic form, yet, 

 nevertheless, it obeys the rule it professes to break, for the term 

 in the conclusion "The whole of the crew" is a summation of 

 the two terms in the two premisses, viz. " Some of the crew " 

 and " Others of the crew," which together distribute the term 

 used in the conclusion. 



(6) Argument with a conclusion drawn from two negative 

 premisses : 



If No one ever reasons by " logical " methods, 

 and No one always reasons erroneously ; 

 then It is quite possible to reason correctly by non-logical methods. 



Here again we have an argument not expressed syllogistically, 



