亚里士多德解释编—-命题的性质与类型

We will now explain what ought to be laid down.

Those predicates, and terms forming the subject of predication, which  are

acc idental  either  to  the  same  subject or  to  one  another, do  not  combine  to

form a unity. Take the proposition ’man is  white of complexion and musical’.

Whiteness and being musical do not coalesce to form a unity, for they belong

only  accidentally to  the same subject.  Nor yet,  if it were true to  say that that

which  is  white is  musical,  would the  terms ’musical’  and ’white’ form  a  unity,

for it is only incidentally that that which is musical is white; the combination of

the two will, therefore, not form a unity.

Thus, again,  whereas, if a man is both good and a shoemak er, we cannot

combine the  two  propositions  and  say  simply  that he  is  a  good  shoemak er,

we are, at the same time, able to combine the predicates ’animal’ and ’biped’

and say that  a  man  is  an  animal  with two  feet,  for these predicates  are not

acc idental.

Those predicates, again, cannot form a unity, of which the one is implicit in

the other: thus we cannot combine the predicate ’white’ again and again with

that  which already contains  the notion  ’white’,  nor  is it  right  to call  a  man  an

animal-man  or  a  two-footed  man;  for  the  notions  ’animal’  and  ’biped’  are

implicit in the word ’man’. On the other hand, it is possible to predicate a term

simply of any one instance, and to say that some one particular man is a man

or that some one white man is a white man.

Yet this is  not always  possible:  indeed,  when in the  adjunct there is  some

opposite which  involves a c ontradiction, the predication of the simple term is

impossible. Thus it is not right to call a dead man a man. When, however, this

is not the case, it is not impossible.

Yet  the  facts  of  the  cas e  might  rather  be  stated  thus:  when  some  such

opposite  elements  are  present,  resolution  is  never  possible,  but  when  they

are  not  present,  resolution  is  nevertheless  not  always  possible.  Take  the

proposition ’Homer is so-and-so’, say ’a poet’; does it follow that Homer is, or

does   it  not?  The  verb  ’is’  is  here  used  of  Homer  only  incidentally,  the

proposition  being  that  Homer  is  a  poet,  not  that  he  is ,  in  the  independent

sense of the word.

Thus,  in  the  case  of  those  predications  which  have  within  them  no

contradiction when the nouns are expanded into definitions, and wherein the

predicates  belong  to  the  subject  in  their  own  proper  sense  and  not  in  any

indirect  way, the  individual  may be  the subject of  the simple propositions  as

well as of the composite. But  in the  case of  that  which is  not,  it is not true to

say that because it is the object of opinion, it is; for the opinion held about it is

that it is not, not that it is.