Critical Thinking Core Concepts

Filling in Implicit Premises

2. See if there is a conclusion that will follow from the premises given.

3. If necessary, provide such a conclusion, or re-word the given conclusion to make it more reasonable (retaining the meaning)

4. Look at the presuppositions of the premises so far for any additional implicit premises.

5. Avoid obviously false or questionable premises (unless they are explicit or a central presupposition of the argument.)

In short, there are two ways to see where and which implicit premises will need to be added:

• (a). look at the argument structure compared with the known valid argument structures to see what is needed, or
• (b). look at the presuppositions of the argument for clues as to what might be (reasonably) added.

Be aware that not all arguments will be as simple as the ones we have been looking at. The formal structure of an argument in the wild will be complicated by (a) compounded compound statements (which will need to be broken down), (b) nested arguments which result in secondary conclusions which support the main conclusion- these arguments will need to be assessed on their own merits for validity and soundness.

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Inquiries to: michael.connelly@mcckc.edu
Last modified: 03/02/04