This is exclusive

The fallacy of exclusive premises

PIRIE, MADSEN (2006)(2015) How To Win Every Argument, Bloomsbury, London.

Pirie

'The standard three-line argument called a syllogism has two premises and a conclusion, the premises are the evidence and the conclusion is deduced from them.

If both of the premises are negative, no conclusion can be validly drawn from them and the fallacy is called the fallacy of exclusive premises.' (98).

Pirie's example of this fallacy:

'No handymen are bakers, and no bakers are fishermen, so no handymen are fisherman'. (98).

This fallacy incorrectly excludes one category of persons from another category of persons, without sufficient evidence to do so. Pire explains: "...some people genuinely believe that if a group is excluded from something, and that group is excluded from something else, than the first group is also excluded from it.' (99).

In the religious studies context, no baptist is charismatic, no charismatic is Reformed, therefore no baptist is Reformed, should be the type of reasoning strictly avoided!

Lander University: Philosophy

Greenwood, South Carolina

Cited 

[The Fallacy of Two Negative Premisses or Exclusive Premisses[ 

"No internal combustion engines are nonpolluting power plants, and no nonpolluting power plants are safe devices. Therefore, no internal combustion engines are safe devices."

Cited 

'This information is of no use to see how the terms in the conclusion are related.'

In other words, the claims are shown as invalid as the connection between them is not clearly presented by the claims provided. Further, I was taught at British, PhD level to avoid the use of negative premises and conclusions, (especially when preparing survey questionnaires) and I attempt to follow this on my website. This approach does assist with both clarity and in avoiding potentially fallacious presentations.

Lander University is helpful here from the link provided: 

Cited 

'Note also that both premisses are negative. As most people are intuitively aware, knowledge about what a thing is not, does not carry much information about what that thing is.' 

Agreed.

Lander in agreement with Pirie:

Cited

'Our Rule of Quality states that no standard form syllogism with two negative premisses is valid.'

Within a valid syllogism argument, a negative conclusion requires a negative premise, to avoid a formal fallacy. But again, I attempt to avoid the use of negative premises.

Langer

Using symbolic logic with positive statements:

Key

∃! is There exists

h is handyman

b is bakers

f is fisherman

(∃!) h=b (There exists (∃!)  handyman that are bakers)

(∃!) b=f  (There exists bakers that are fisherman)

(∃!) h=f  (There exists handymen that are fishermen)

There exists (∃!)  handyman that are bakers. There exists bakers that are fisherman. There exists handymen that are fishermen. This is reasonable, think Alaska, small rural America, Northern Canada, Northern Russia, Northern China, as hypothetical examples.

I managed to slip in a review of both philosophy texts, under review from cover to cover, on this website, in one entry...

BLACKBURN, SIMON (1996) Oxford Dictionary of Philosophy, Oxford, Oxford University Press.

CONWAY DAVID A. AND RONALD MUNSON (1997) The Elements of Reasoning, Wadsworth Publishing Company, New York.

LANDER UNIVERSITY (1997-2020)  Syllogistic Fallacies Philosophy 103: Introduction to Logic Syllogistic Fallacies: Exclusive Premisses 

https://philosophy.lander.edu/logic/exclusive_fall.html 

LANGER, SUSANNE K (1953)(1967) An Introduction to Symbolic Logic, Dover Publications, New York.

PIRIE, MADSEN (2006)(2015) How To Win Every Argument, Bloomsbury, London.

November 19, 2016 article edited for an entry on academia.edu on July 15, 2023