ONT Re: De In Esse Predication
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DEIP. Note 8
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| The consequence 'de inesse', "if A is true, then B is true",
| is expressed by letting i denote the actual state of things,
| A_i mean that in the actual state of things A is true, and
| B_i mean that in the actual state of things B is true, and
| then saying "If A_i is true then B_i is true", or, what is
| the same thing, "Either A_i is not true or B_i is true".
|
| But an 'ordinary' Philonian conditional is expressed
| by saying, "In 'any' possible state of things, i,
| either A_i is not true, or B_i is true".
|
| Now let us express the categorical proposition,
| "Every man is wise". Here, we let m_i mean that
| the individual object i is a man, and w_i mean that
| the individual object i is wise. Then, we assert that,
| "taking any individual of the universe, i, no matter
| what, either that object, i, is not a man or that
| object, i, is wise"; that is, whatever is a man
| is wise. That is, "whatever 'i' can indicate,
| either m_i is not true or w_i is true".
|
| The conditional and categorical propositions
| are expressed in precisely the same form;
| and there is absolutely no difference,
| to my mind, between them. The 'form'
| of relationship is the same.
|
| C.S. Peirce, 'Collected Papers', CP 3.444-445,
|"The Regenerated Logic", 'Monist', vol. 7,
| pp. 19-40, 1896.
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