AND ON LOGIC IN GENERAL. 221 



1. VVV. If there be only one particular term in the conclusion, that term takes the 

 whole quantity or force of the other term : but if there be two particular terms, one has the 

 quantity or force of the middle term, the other of its contrary. 



2. VVP. The particular term, or both if there be two, takes quantity or force from 

 the whole middle term, if the middle term be universal in both premises ; and from the whole 

 contrary of the middle term, if the middle term be particular in both premises. 



3. PVP and VPP. The particular term or terms in the conclusion take quantity or 

 force from the particular term in the premise. 



For example, let X )) Y )) Z give X )) Z in the form x (•) Z, with both terms particular. 

 Everything is either x or Z. What extent of x are we sure of.' an extent equal to that of y. 

 And of Z, to fill up the universe, there remains the whole extent of Y. 



Again, to apply symbols to a material example, 



health ]] temperance ]] sobriety gives health ]•[ excess in liquor. 



The conclusion has both terms intensively particular. The forces of the repugnant terms 

 health and [habit of] intoxication, are merely those of temperance and intemperance : health is 

 a more intensive term than temperance, but we have not, in the argument, to do with any 

 essential of health except temperance ; or with any essential of intoxication except intemper- 

 ance. Or, as people will sometimes say, ' to shew that health and intoxication are repugnant, 

 it is enough to say that temperance is not intemperance.' This seems to many to be only 

 a metaphorical heightening of contrast by substitution of explicit force of verbal contrariety 

 for things which are as repugnant as contraries. But it is not so : it means that the inten- 

 sive forces of a conclusion are in thought, and ought to have been in logic. The world sees 

 — without knowing precisely what it sees — that the abacus process — " All healthy is temperate ; 

 all temperate is sober ; therefore all healthy is sober : but no sober is drunken ; therefore no 

 healthy is drunken ' — does not express its form of thought, though it be Barbara and Cela- 

 rent in one. 



XLI. The first figure is the most commodious : the fourth is nothing but the first with 

 its conclusion read backwards ; both these have been completely canonised. The symbolic 

 rules for the second and third figures are very easily deduced: but I shall not swell this paper 

 with them. If we consider premises only, there are but three figures. Each conclusion reads 

 in two orders, which is no variation in two of the figures, and makes all the distinction between 

 the first and the fourth. Now if we remember that premises are imposed upon us, but order 

 of conclusion is our own choice, we see that the fourth figure is our own doing. 



When both premises are mathematical, or both metaphysical, figure is a truly unessential 

 variation, if the mind be equally accustomed to all modes of perceiving validity. All the duties 

 which have been appropriated to the several figures seem to me to be fictions, so long as there 

 is but one kind of reading. When the two propositions are of different readings, there is then 

 a difference in the form of thought in different figures. The cases in which this occurs must 

 be those in which the middle term is of the same reading in both, a mode of thought which 

 must come first or last. 



In the physical and contraphysical forms, it is not necessary to invent more schetical 

 words: any term may be carried to another by its own reading. Thus we may call class a 



