GHL to Clement Mansfield Ingleby, London, [12 October 1871]
Title
GHL to Clement Mansfield Ingleby, London, [12 October 1871]
Title
GHL to Clement Mansfield Ingleby, London, [12 October 1871]
Sender
George Henry Lewes
Recipient
Clement Mansfield Ingleby
Date(s)
- 1871-10-12
Place
London
Letter Content
GHL to Clement Mansfield Ingleby, London, [12 October 1871]
MS: Folger Library.
The Priory, | 21. North Bank, | Regents Park.
Thursday.
My dear Sir
First let me say in justice to Jevons that you misunderstood me, or I expressed myself quite inaccurately. His machine 55 does not turn out the false conclusion from the true premises in such an example as No man is a stone etc. but simply that "A man is either an animal or not an animal." But his machine does justify Aristotle's example and thereby proves my case -- which is the vanity of the mere syllogistic form.
My point is this: The syllogism is a mill which grinds fatally; all depends on what is put into it to be ground. You seem to consider Aristotle's example a true syllogism and my inversion of it a false one. I consider that both are true as forms, and that both conceal a paralogism and if this concealed paralogism be dragged into light, the whole is clear. Thus every man is a stone (man) every stone (man) is an animal [therefore] every (stone) is an animal (stone). Although the proposition every man is an animal, when isolated, is true, this is not the conclusion shut up in the premises unless stone man and stone animal be understood. The judgment really is "Whatever man is animal is"; if man is stone man, and stone man is animal stone, then -- Alter it into every man is a stone; every stone is a carrot [therefore] Every man is a carrot. Here the conclusion is as obviously false as the premise. Yet it says: what man is stone is i.e. carrot.
I think therefore that if the Aristotelian form is correct, the inversion of it is equally so; and the conclusion is: No (stone) man is a (stone) animal: which is what the premises assert. If I say: No animal is-immortal: Dogs are-animals: no dog is-immortal -- is not the form correct -- and wherein (as form) does it differ from No man is-a stone etc.?
I am but superficially versed in Logical literature, but as far as I understand the syllogism it is that the conclusion is simply an explication of which is implicated in the premises, whatever that may be; and therefore the truth or falsity of a conclusion never resides in the form but in the matter. You will correct me if I am wrong; and since logicians have as far as I know always maintained that a true conclusion could be deduced from false premises (which I deny) they ought to maintain that a false conclusion can equally be deduced from true premises. In either case it is necessary that the paralogism should occur, so that the conclusion expresses something not really given in the premises.
You will see that the gist of the matter is this: Can we deduce from premises what is not already shut up in them? And is not the false conclusion proof of a paralogism?
Yours in haste
G. H. Lewes.
MS: Folger Library.
The Priory, | 21. North Bank, | Regents Park.
Thursday.
My dear Sir
First let me say in justice to Jevons that you misunderstood me, or I expressed myself quite inaccurately. His machine 55 does not turn out the false conclusion from the true premises in such an example as No man is a stone etc. but simply that "A man is either an animal or not an animal." But his machine does justify Aristotle's example and thereby proves my case -- which is the vanity of the mere syllogistic form.
My point is this: The syllogism is a mill which grinds fatally; all depends on what is put into it to be ground. You seem to consider Aristotle's example a true syllogism and my inversion of it a false one. I consider that both are true as forms, and that both conceal a paralogism and if this concealed paralogism be dragged into light, the whole is clear. Thus every man is a stone (man) every stone (man) is an animal [therefore] every (stone) is an animal (stone). Although the proposition every man is an animal, when isolated, is true, this is not the conclusion shut up in the premises unless stone man and stone animal be understood. The judgment really is "Whatever man is animal is"; if man is stone man, and stone man is animal stone, then -- Alter it into every man is a stone; every stone is a carrot [therefore] Every man is a carrot. Here the conclusion is as obviously false as the premise. Yet it says: what man is stone is i.e. carrot.
I think therefore that if the Aristotelian form is correct, the inversion of it is equally so; and the conclusion is: No (stone) man is a (stone) animal: which is what the premises assert. If I say: No animal is-immortal: Dogs are-animals: no dog is-immortal -- is not the form correct -- and wherein (as form) does it differ from No man is-a stone etc.?
I am but superficially versed in Logical literature, but as far as I understand the syllogism it is that the conclusion is simply an explication of which is implicated in the premises, whatever that may be; and therefore the truth or falsity of a conclusion never resides in the form but in the matter. You will correct me if I am wrong; and since logicians have as far as I know always maintained that a true conclusion could be deduced from false premises (which I deny) they ought to maintain that a false conclusion can equally be deduced from true premises. In either case it is necessary that the paralogism should occur, so that the conclusion expresses something not really given in the premises.
You will see that the gist of the matter is this: Can we deduce from premises what is not already shut up in them? And is not the false conclusion proof of a paralogism?
Yours in haste
G. H. Lewes.
Signature
G. H. Lewes.
Citation
George Henry Lewes, GHL to Clement Mansfield Ingleby, London, [12 October 1871], Complete George Eliot Letters(2026), George Eliot Archive, edited by Beverley Park Rilett. https://GeorgeEliotArchive.org, Accessed September 7, 2026. https://www.georgeeliotarchive.org/items/show/94489