Summary
Summary PHI1025F Test 2 Preparatory Notes
- Course
- PHI1025F Critical Thinking
- Institution
- University Of Cape Town (UCT)
This is a comprehensive and detailed preparatory note for test 2. Essential!!
[Show more]
Content preview
● If [sufficient condition], then [necessaryRecap condition].
Valid Argument - if we assume the premises are Antecedent - “sufficient condition”; it is enough to
true, then the conclusion has to be true. bring about the consequent.
We use the 3 valid argument forms (Modus Ponens, Consequent - “necessary condition”; it MUST
Modus Tollens, or Eliminative Syllogism) to assess occur if the antecedent occurs.
validity. “Only If” - a necessary condition
Modus Ponens ● “Only if” is not the same as “if”.
1. If P, then Q. ● After “only if” is the consequent.
2. P. ● Remove “only if” when re-writing the
3. So, Q. conditional.
Modus Tollens “Must” - a necessary condition
1. If P, then Q. 1. If M, then not-F. ● What “must be done” is the consequent.
2. Not-Q. 2. F. “Required” - a necessary condition
3. So, not P. 3. So, not-M.
● What is “required” to occur is the
1. If M, then F. consequent.
2. Not-not F.
“Necessary For” - a necessary condition
3. So, not-not M.
● What is “necessary for” is the consequent.
Eliminative Syllogism / Disjunctive Syllogism
“Sufficient For” - sufficient condition
● There are no conditionals in eliminative
syllogisms, there are disjuncts which make ● What is “sufficient for” is the antecedent.
up a disjunction. “Sufficient Condition” - sufficient condition
● Disjunctions are “Either P or Q.” claims. ● The “sufficient condition” is the antecedent.
● P and Q are disjuncts. “Unless”
● A disjunction is true if at least 1 of the ● When re-writing the conditional, replace
disjuncts is true. “unless” with “if … not [antecedent], then
(not) [consequent]”.
1. Either P or Q. 1. Either P or Q.
2. Not-Q. 2. Not-P. Informal Fallacies
3. So, P. 3. So, Q.
● Fallacy - is an error in reasoning.
Good Deductive Arguments - are valid and sound.
● Fallacious Argument - the premises do not
Soundness - an argument that is valid with all true support the truth of the conclusion.
premises and a true conclusion.
● Informal Fallacies - are defective arguments
Unsoundness - an argument that is invalid with at due to the content of the premises, but are
least 1 true premise. not necessarily invalid.
Conditionals Informal Fallacies of Evidence
● If [antecedent], the [consequent].
1
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through EFT, credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying this summary from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller anyiamgeorge19. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy this summary for R206,76. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83637 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy summaries for 14 years now