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Where the syllogism "All men are mortal / Socrates is a man / Therefore, Socrates is mortal" first appeared?

tatojo
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  • Did you notice that later in the article, making it part of the conclusion, the author uses the expression “identical to Socrates”? I can say that the expression is redundant because “The only thing identical to Socrates is Socrates.” Law of Identity, A is A, Aristotle. – user48454 Sep 23 '20 at 15:09

2 Answers2

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Comment on similar example.

The example is not from Aristotle.

Categorical propositions with singular terms are used in Medieval logic; see Peter of Spain's Summulae logicales (XIII century):

I,8 Propositio singularis est illa [...], ut "Sortes currit" [Socrates runs].

Into this textbook we can find many examples of them in the discussion of loci and entimema [V,3], bt it seems to me that there is no occurrence of the specific example of syllogism.

According to: Joseph Maria Bochenski, A History of Formal Logic (1961, or.ed.1956), page 232:

A first widening of the Aristotelian syllogistic consists in the admission of singular terms and premisses. William of Ockham (c.1287–1347) already knows of the substitution that was to become classic [Summa Logicae, III 1,3;36rb]:

Every man is an animal;

Socrates is a man;

Therefore, Socrates is an animal.

Here the minor premiss is singular. But Ockham also allows singular propositions as major premisses.

The earliest occurrence I've found is:

Socrates is human.

Everything human is an animal.

Therefore, Socrates is an animal.

Mauro ALLEGRANZA
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Per David A. Wheeler's article "The Origin of All Men are Mortal" (which elsewhere cites this page!)

The earliest document I can find with this specific example is from 1843, specifically A System of logic: Ratiocinative and Inductive, Presenting a Connected View of the Principles of Evidence and the Methods of Scientific Investigation by John Stuart Mill, 1843, Book II Chapter 3 page 245.

One can indeed see the quote

2. It must be granted that in every syllogism, considered as an argument
to prove the conclusion, there is a petitio principii. When we say,

All men are mortal
Socrates is a man
  therefore
Socrates is mortal ;

it is unanswerably urged by the adversaries of the syllogistic theory,
that the proposition, Socrates is mortal, is presupposed in the more
general assumption, All men are mortal:

in the Internet Archive's copy of Mill's System of Logic.

TomRoche
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