Lecture Notes

Lecture Notes by Christopher Lay

Los Angeles Pierce College

Department of History, Philosophy, and Sociology

Mathew Van Cleave's 2016 Introduction to Logic and Critical Thinking

https://open.umn.edu/opentextbooks/BookDetail.aspx?bookId=457

Chapter 1 "Reconstructing and Analyzing Arguments"

§2 "Identifying arguments"

Indicators

"The best way to identify whether an argument is present is to ask whether there is a statement that someone is trying to establish as true by basing it on some other statement."

Because

"The word 'because' here is a premise indicator. That is, 'because' indicates that what follows is a reason for" accepting some conclusion.

Since

"[T]he word 'since' is a premise indicator because what follows it is a statement that is clearly intended to be a reason for thinking that" some conclusion should be accepted.

"[T]he word 'so' is a conclusion indicator because what follows it is a statement that someone is trying to establish as true (i.e., a conclusion)."

Therefore

"[T]he word 'therefore' is a conclusion indicator because what follows it is a statement that someone is trying to establish as true (i.e., a conclusion)."

Premise indicators	Conclusion indicators
since	therefore
because	so
for	hence
as	thus
given that	implies that
seeing that	consequently
for the reason that	it follows that
is shown by the fact that	we may conclude that

Caution with Indicator Words

"Just because a sentence contains them does not mean that you are dealing with an argument."

"[T]he best way to determine whether an argument is present is by asking the question: Is there a statement that someone is trying to establish as true or explain why it is true by basing it on some other statement?"

"[B]oth premise indicators and conclusion indicators are, grammatically, conjunctions."

"A grammatical conjunction is a word that connects two separate statements. So, if a word or term is truly being used as a premise or conclusion indicator, it must connect two separate statements."

The Substitution Test

"If there is any doubt about whether a word is truly a premise/conclusion indicator or not, you can use the substitution test. Simply substitute another word or phrase from the list of premise indicators or conclusion indicators and see if the resulting sentence still makes sense."

Exercise 2