Cf: Peirce’s 1870 “Logic of Relatives” • Comment 9.1
https://inquiryintoinquiry.com/2014/02/24/peirces-1870-logic-of-relatives-c…
Re: Peirce’s 1870 “Logic of Relatives” • Selection 8
https://inquiryintoinquiry.com/2014/02/17/peirces-1870-logic-of-relatives-s…
Re: Peirce’s 1870 “Logic of Relatives” • Selection 9
https://inquiryintoinquiry.com/2014/02/23/peirces-1870-logic-of-relatives-s…
All,
Perspective on Peirce’s use of the comma operator at CP 3.73 and CP 3.74 can
be gained by dropping back a few years and seeing how George Boole explained
his twin conceptions of “selective operations” and “selective symbols”.
<QUOTE Boole>
Let us then suppose that the universe of our discourse is the actual universe,
so that words are to be used in the full extent of their meaning, and let us
consider the two mental operations implied by the words “white” and “men”.
The word “men” implies the operation of selecting in thought from its subject,
the universe, all men; and the resulting conception, men, becomes the subject
of the next operation. The operation implied by the word “white” is that
of selecting from its subject, “men”, all of that class which are white.
The final resulting conception is that of “white men”.
Now it is perfectly apparent that if the operations above described had been
performed in a converse order, the result would have been the same. Whether
we begin by forming the conception of “men”, and then by a second intellectual
act limit that conception to “white men”, or whether we begin by forming the
conception of “white objects”, and then limit it to such of that class as are
“men”, is perfectly indifferent so far as the result is concerned. It is
obvious that the order of the mental processes would be equally indifferent
if for the words “white” and “men” we substituted any other descriptive or
appellative terms whatever, provided only that their meaning was fixed and
absolute. And thus the indifference of the order of two successive acts
of the faculty of Conception, the one of which furnishes the subject upon
which the other is supposed to operate, is a general condition of the
exercise of that faculty. It is a law of the mind, and it is the real
origin of that law of the literal symbols of Logic which constitutes
its formal expression (1) Chap. II [xy = yx].
It is equally clear that the mental operation above described is of such
a nature that its effect is not altered by repetition. Suppose that by
a definite act of conception the attention has been fixed upon men, and
that by another exercise of the same faculty we limit it to those of the
race who are white. Then any further repetition of the latter mental act,
by which the attention is limited to white objects, does not in any way
modify the conception arrived at, viz., that of white men. This is also
an example of a general law of the mind, and it has its formal expression
in the law (2) Chap. II [x^2 = x] of the literal symbols.
(Boole, Laws of Thought, 44–45)
</QUOTE>
Regards,
Jon