Cf: Peirce’s 1870 “Logic of Relatives” • Comment 8.6
https://inquiryintoinquiry.com/2014/02/23/peirces-1870-logic-of-relatives-c…
Peirce’s 1870 “Logic of Relatives” • Comment 8.6
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https://oeis.org/wiki/Peirce%27s_1870_Logic_Of_Relatives_%E2%80%A2_Part_1#C…
All,
The foregoing has hopefully filled in enough background that we
can begin to make sense of the more mysterious parts of CP 3.73.
<QUOTE CSP>
The Signs for Multiplication (cont.)
Thus far, we have considered the multiplication of relative terms only.
Since our conception of multiplication is the application of a relation,
we can only multiply absolute terms by considering them as relatives.
Now the absolute term “man” is really exactly equivalent to the
relative term “man that is ──”, and so with any other. I shall
write a comma after any absolute term to show that it is so
regarded as a relative term.
Then “man that is black” will be written:
m,b.
(Peirce, CP 3.73)
</QUOTE>
In any system where elements are organized according to types
there tend to be any number of ways in which elements of one
type are naturally associated with elements of another type.
If the association is anything like a logical equivalence,
but with the first type being lower and the second type
being higher in some sense, then one may speak of a
“semantic ascent” from the lower to the higher type.
For example, it is common in mathematics to associate an
element _a_ of a set A with the constant function fₐ : X → A
which has fₐ(x) = a for all x in X, where X is an arbitrary
set which is fixed in the context of discussion. Indeed, the
correspondence is so close that one often uses the same name “a”
to denote both the element a in A and the function a = fₐ : X → A,
relying on context or an explicit type indication to tell them apart.
For another example, we have the “tacit extension” of a k-place relation
L ⊆ X₁ × … × Xₖ to a (k+1)-place relation L′ ⊆ X₁ × … × Xₖ₊₁ which we get
by letting L' = L × Xₖ₊₁, that is, by maintaining the constraints of L on
the first k variables and letting the last variable wander freely.
What we have here, if I understand Peirce correctly, is another such
type of natural extension, sometimes called the “diagonal extension”.
This extension associates a k-adic relative or a k-adic relation,
counting the absolute term and the set whose elements it denotes
as the cases for k = 0, with a series of relatives and relations
of higher adicities.
A few examples will suffice to anchor these ideas.
Absolute Terms
==============
m = man = C +, I +, J +, O
n = noble = C +, D +, O
w = woman = B +, D +, E
Diagonal Extensions
===================
m, = man that is____ = C:C +, I:I +, J:J +, O:O
n, = noble that is____ = C:C +, D:D +, O:O
w, = woman that is____ = B:B +, D:D +, E:E
Sample Products
===============
m,n = man that is a noble
= (C:C +, I:I +, J:J +, O:O)
×
(C +, D +, O)
= C +, O
n,m = noble that is a man
= (C:C +, D:D +, O:O)
×
(C +, I +, J +, O)
= C +, O
w,n = woman that is a noble
= (B:B +, D:D +, E:E)
×
(C +, D +, O)
= D
n,m = noble that is a woman
= (C:C +, D:D +, O:O)
×
(B +, D +, E)
= D
Regards,
Jon