Critical Reasoning Flashcards
Modus Tollens
- Negative
- E.g. If the building had been broken into the alarm would have sounded, the alarm did not sound so there was no break in
Modus Ponens
- Positive
- E.g. If there is a south westerly blowing, the surf will be good. There is a south westerly blowing so the surf will be good
Inductive
- Even if both premises are true it is still possible for the conclusion to be false
- conclusion > main points > supporting data and evidence
- E.g. All tigers observed within this region have black stripes. Therefore, all the tigers from this region will have black stripes
Deductive
- It is impossible for the premise to be true but the conclusion false
- 1=2, and 2=3, then 1=3
- E.g. All fruit grow on trees, as orange is a fruit, therefore an orange grows on a tree
Description
Typically gives one or more items of information about a particular topic
Narrative
Describes or portrays actions in time
Explanation
We already accept the truth of a statement but we try to say how it is that it came about
Argument
Aims to justify the truth of some statement by giving reasons for it
Conclusion Indicators
Therefore, so, thus, which proves that, which shows that, from which it follows that, consequently, which leads to, which is why, what follows from this is obvious
Reason Indicators
Because, due to the fact that, is based on, is proved by, is shown by, which follows from, is a consequence of, since, for
NOT Indicators
However, but, and, moreover, in addition, or, if, then, unless, conversely
To evaluate any argument 4 questions need to be asked
- What conclusion is being drawn?
- What reasons are being given for the conclusion?
- How likely is it that the reasons are true?
- How strongly do the reasons support the conclusion?
Cogent
clear, logical, convincing, true, realistic
5 Different degrees of strength in inferences
- Deductively valid (100% certain)
- Strong (75% - 99.9% certain)
- Moderate (25% - 75% certain)
- Weak (1% to 25% certain)
- Nil (0% certain)
Formal Logic
Logic that is neat and tidy where the inferences are regarded as only of two types: deductively valid or not deductively valid
Informal Fallacies
Fallacies that can’t be neatly symbolised or formalised. A miscellaneous bunch of mistakes.
Ad Hominem Arguments
Attacking the person rather that the argument they put forward
Argument from irrelevant authority
When a person who is an expert in one area is presented as an expert in another area
The genetic fallacy
To attack an argument not in terms of its content but in terms of its origins
Hasty Generalisation
Jumping to a general conclusion from only a small sample
Argument from ignorance
- We do not know that X is true, therefore it is false
OR - We do not know that X is false, therefore it is true
Equivocation
Using a word or phrase that shifts from one meaning to another in an argument, making the argument seam cogent when it is not
Denying the Antecendent
- Modus Tollen just not deductively valid
- Negative
- E.g. If the roads are slippery and wet, then you need to drive carefully. But the roads are not slippery and wet, so you don’t need to drive carefully
Affirming the consequent
- Modus Ponen just not deductively valid
- Positive
- E.g. If my computer breaks down, I won’t be able to write my essay. I am not able to write my essay, so my computer has broken down
- Summary
- Identify the main position of each participant
- Clarification
- Concepts - State the philosophical concepts that frame the argument of each participant
- Arguments - Explain all arguments with relative examples. Describe all arguments
- Evaluation
- Examples - Explain the relevance of all examples used
- Premises - provide reasons to justify the stated acceptability of all premises. State the acceptability of all premises
- Inferences - State the strength of all inferential moves and provide reasons to justify it
- Cogency - Assess the cogency of each argument
