10 EDWARD D. SIMMONS 



St. Thomas speaks of these " basic truths " as per se nota 

 propositions. Although this is an apt expression, there is some 

 danger of confusion here. First of all, St. Thomas may some- 

 times use the term per se nota of a proposition which is not 

 evident in the way in which the basic truths of demonstration 

 are self-evident." Secondly, St. Thomas frequently speaks of 

 the modes of perseity (the modi dicendi per se) ,^" and, despite 

 the terminological suggestion to the contrary, it is not true that 

 whenever we have a proposition which involves a mode of 

 perseity we have a per se nota or self-evident proposition. 

 These points will have to be clarified before we are through. 



For the premises of demonstration to be at all they must 

 be true, for the esse of a proposition is an esse verum. For 

 them to be principles of manifestation for the scientific con- 

 clusion they must be necessarily true, for necessity is of the 

 essence of science. And for them to be basic truths, that is 

 absolute premises, the premises of demonstration must be, at 

 least reductively, imviediate propositions. Here is precisely 

 where the scientific proposition differs from its pre-scientific 

 principle. The scientific proposition is necessarily true, and it 

 is a conclusion. The scientific principle is necessarily true, but 

 it can be (ultimately) in no sense a conclusion. The conclusion 

 of a syllogism is characteristically mediate, for the connection 

 between its extremes is manifested in a syllogism by way of a 

 term commonly identified with both extremes, thus functioning 

 as a middle. The basic truths of syllogism or the absolute 

 premises must themselves be evident without a middle. The 

 predicate must belong immediately to the subject lest we admit 

 the infinite regress which would make deduction totally ineffec- 

 tive. Two things, at least, should be pointed out here. First of 

 all, there is a significant and not unrelated use of the term 

 " immediate " which is not intended at this point. For example, 

 having three angles equal to two right angles is necessarily 



^^ In II Pkys., lect. 1, n. 8: " Naturam autem esse, est per se notum, in quantum 

 naturalia sunt manifesta sensui." 



" Cf., In I Post. Anal., lect. 10; In II De Anima, lect. 14, n. 401; In V Met., lect. 

 19, nn. 1054-1057. 



