Comments about "Modus ponens" in Wikipedia

This document contains comments about the article Modus ponens in Wikipedia
In the last paragraph I explain my own opinion.

Contents

Reflection

Introduction

The article starts with the following sentence.
Modus ponens is closely related to another valid form of argument, modus tollens.
What defines a valid form of argument?
The history of modus ponens goes back to antiquity
Okay
The first to explicitly describe the argument form modus ponens was Theophrastus.
Okay.
It, along with modus tollens, is one of the standard patterns of inference that can be applied to derive chains of conclusions that lead to the desired goal.
The desired goal of what?

1. Explanation

An example of an argument that fits the form modus ponens:
If today is Tuesday, then John will go to work.
Today is Tuesday.
Therefore, John will go to work.
The most important part of this argumentation is the first sentence. "If today is Tuesday, then John will go to work." or "Every Tuesday John will go to work". The question is: is this question 100% true. That means John will at least go to work 52 days to work, in health and in poor, under all conditions.
In reality I doubt that.. This same doubt is also part of the next two sentences.

2 Formal notation

3 Justification via truth table

4 Status

5 Correspondence to other mathematical frameworks

5.1 Probability calculus

5.2 Subjective logic

6 Alleged cases of failure

The philosopher and logician Vann McGee has argued that modus ponens can fail to be valid when the consequent is itself a conditional sentence.
Okay.
Here is an example:
Either Shakespeare or Hobbes wrote Hamlet. If either Shakespeare or Hobbes wrote Hamlet, then if Shakespeare didn't do it, Hobbes did. Therefore, if Shakespeare didn't write Hamlet, Hobbes did it.
If the first sentence is true that means that Hamlet is written by one author and this can be either S or H than the other two sentences don't make sense; add nothing to the argument.
As such if further research shows that S didn't do it then H did.
Or the reverse if H didn't do it then S did.

7 Possible fallacies

8. See also

Following is a list with "Comments in Wikipedia" about related subjects

Reflection 1 - Proper Science and Proper Argumentation.

The most important issue in science is that what you write should be clear and unambiguous.
In fact all what you write should be true or you should mention the opposite.

One important reason of this particular is the article The False Logic of Science Denial in Scientific American of August 2020

Reflection 2

Reflection 3

Feedback

If you want to give a comment you can use the following form Comment form
Created: 16 August 2020

Go Back to Wikipedia Comments in Wikipedia documents
Back to my home page Index