Saturday, August 02, 2014

Types Of Arguments

Biarritz, France-Travel+Leisure, Facebook

























I still need to write a post while at or near water like that...

Thursday late night after work @ Safeway, a man behind me in line states: 'You look more like a banker than security'.

Types Of Arguments

I receive a newsletter from 'Reasons to Believe' which writes on science and Christian faith from an old earth/non-Darwinian perspective.

The short article 'How to Evaluate an Abductive Argument' is informative and interesting in comparison to The Elements of Reasoning text and other philosophical reading I used as source while writing arguments for my academic theses.

Kenneth Samples begins by stating that logic provides a checklist for thoughts and allows beliefs to be presented in a clear consistent manner.  Reasons (2014: 2).

The idea is that this assists in Christian faith and philosophy.

Reasonable.

Samples notes three approaches in logic:

Deduction, which establishes with certainty true conclusions

Induction, which establishes probably true conclusions

Abduction, which uses a set of established facts to infer the best explanation. Samples admits the abduction method is less well-known. Reasons (2014: 2).

Reviewing my 'Elements' text, it appears that abductive argumentation is not reviewed.

Inductive arguments are mentioned in the context of 'inductive generalization' where the inference is from some sample of a population to all or some percentage of its members. Elements (1997: 43).

The authors state that there is no 'simple answer' to support evidence for an inductive generalization but statistics are used to avoid 'gross errors'. Elements (1997: 43).

The authors then contrast induction from deduction.The two types of arguments are contrasted. Nondeductive are contrasted from deductive arguments and the terms inductive and induction are used for 'reasoning that generalizes from particular instances'. Elements (1997: 43).

Blackburn explains that inductive reasoning (and therefore the arguments I reason) would be used in any process of reasoning that takes place with empirical premises to empirical conclusions. Blackburn 1996: 192).

Deductive arguments are meant to be valid, that is their premises are meant to guarantee the conclusion. A nondeductive argument has premises with a 'likely' conclusion. Elements (1997: 33). This makes sense based on the empirical approach of inductive reasoning.

In contrast deductive arguments draw a conclusion from a set of premises. Blackburn (1996: 96).

This would be the approach used more within academic philosophy and theology.

Blackburn reviews abduction as the process by which evidence is gathered in order to reach a wider conclusion as inference as the best explanation. The results subject to rational evaluation. Blackburn (1996: 1).

Note:

Validity in deductive arguments is a technical term in logic. Elements (1997: 33).

If the premises are true, the conclusion must be true. The concept of true premises and false conclusion would be 'inconceivable in a valid argument'. Elements (1997: 33).

Validity is a set of premises supporting a conclusion. Technically in logic the premises do not have to be true, simply valid. Elements (1997: 33).

Therefore a valid deductive argument can have

False premises and a true conclusion (FT)

False premises and a false conclusion (FF)

True premises and a true conclusion (TT)

However

True premises and a false conclusion (TF) is invalid.

Valid arguments with all true premises are called sound arguments. These also have a true conclusion.

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.

SAMPLES, KENNETH (2014) How to Evaluate an Abductive Argument, Reasons to Believe, Covina, California.