Cf: Peirce’s 1870 “Logic of Relatives” • Selection 10
https://inquiryintoinquiry.com/2014/03/09/peirces-1870-logic-of-relatives-s…
All,
We continue with §3. Application of the Algebraic Signs to Logic.
Peirce’s 1870 “Logic of Relatives” • Selection 10
=================================================
https://oeis.org/wiki/Peirce%27s_1870_Logic_Of_Relatives_%E2%80%A2_Part_1#S…
<QUOTE CSP>
The Signs for Multiplication (cont.)
The sum x + x generally denotes no logical term.
But x,_∞ + x,_∞ may be considered as denoting
some two x’s. It is natural to write
[Display 1] x + x = 2.x and x,_∞ + x,_∞ = 2.x,_∞
https://inquiryintoinquiry.files.wordpress.com/2022/01/lor-1870-selection-1…
where the dot shows that this multiplication is invertible.
We may also use the antique figures so that
[Display 2]
https://inquiryintoinquiry.files.wordpress.com/2022/01/lor-1870-selection-1…
Then 2 alone will denote some two things. But this multiplication
is not in general commutative, and only becomes so when it affects
a relative which imparts a relation such that a thing only bears it
to one thing, and one thing alone bears it to a thing. For instance,
the lovers of two women are not the same as two lovers of women, that is,
[Display 3] ℓ2.w and 2.ℓw
https://inquiryintoinquiry.files.wordpress.com/2022/01/lor-1870-selection-1…
are unequal; but the husbands of two women
are the same as two husbands of women, that is,
[Display 4]
https://inquiryintoinquiry.files.wordpress.com/2022/01/lor-1870-selection-1…
(Peirce, CP 3.75)
</QUOTE>
Regards,
Jon