AinA 090 – Types of argument.

Most of what we have said so far applies to deductive arguments. You will recall that

In this course you are also expected to know about

• inductive arguments
• conductive arguments, and
• analogical arguments.

There are also other kinds of argument that you are not required to know about.

It used to be said that there are only two kinds of argument — deductive and inductive. Anything that wasn't deductive was considered inductive. There are problems with this classification for although the kinds of argument listed above do share something important in common there are also important differences between, for example, traditional inductive arguments and conductive arguments. The SQA documentation doesn't take a stance on how to classify these arguments. In the support notes it says about conductive arguments: 'Indeed there is debate amongst philosophers as to whether they count as a form of inductive reasoning or are a separate class of their own.'

It is probably best to say that there are two types of argument:

Deductive arguments & non-deductive arguments

where

That is to say, with non-deductive arguments it is possible for the premises to be true and the conclusion false. It is tempting to say that all non-deductive arguments are, therefore, invalid. However, this isn't really appropriate. 'Valid' and 'invalid' are terms that are applied to deductive arguments. To say a deductive argument is invalid is to say there is something wrong with the argument. Recognising that in non-deductive arguments the premises don't guarantee the conclusion isn't to say there is something wrong with the argument but is, rather, just identifying the distinguishing feature of non-deductive arguments. We will consider later how to evaluate the quality of non-deductive arguments.