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"

§7 "Soundness"

"A sound argument is a valid argument that has all true premises. That means that the conclusion of a sound argument will always be true."

 

Consider this: "if the premises are actually true, as they are in a sound argument, then since all sound arguments are valid, we know that the conclusion of a sound argument is true."

 

 

 

 

 

 

 

 

 

On Soundness and Validity

"[A]ll sound arguments are valid arguments, but not all valid arguments are sound arguments." 

 

 

 

 

 

 

 

 

 

Our Interest in Soundness

"Although soundness is what any argument should aim for, we will not be talking much about soundness in this book."

 

 

 

 

 

 

 

 

 

On Truth

"The relevant disciplines to consult if you want to know whether a particular statement is true is almost never logic!"

 

For us, "it is best to leave the question of what is empirically true or false to the relevant disciplines that study those topics. And that is why the issue of soundness, while crucial for any good argument, is outside the purview of logic."