What Logic can & cannot do - Wesley Salmon

(Originally Written September 1, 2005 in Book 1)

Logic
Wesley C. Salmon
1963

Chapter One: The Scope of Logic

Arguments & Inference:
-Statements are made
-If a statement is made and is supported, then it is an argument
-Arguments (in logic) are not disagreements, but merely statements supported by evidence
-Logical analysis is concerned with the relationship between a conclusion and the evidence used to make the conclusion
-Logical analysis is solely concerned with the relationship of evidence to the conclusion, not the validity or invalidity of the evidence.
-An inference is a supported idea, belief or opinion
-A voiced/penned inference is an argument
-Thus, the conclusion of an argument is a statement, while the conclusion of an inference is an opinion, belief or  an idea
-Premises are statements that support the conclusion

Discovery & Justification
-Discovery: How did it come to be thought of?
-Answers to this question or circumstance pertaining to this question deal with the context of discovery
-Justification: what reasons do we have for accepting it as truth?
-Answers to or circumstances pertaining to this question deal with the context of justification
-It is important not to blur these two questions.
-The justification of a statement consists of an argument and the conclusion
-The discovery of a statement is a psychological process of thought, thought development and acceptance.
-Questions of justification are questions of the acceptability of statements
-Justification is twofold: truth of premises and logical correctness of an argument
-Showing that a justification is inadequate does not prove the conclusion is false
-"Logic deals with justification, not discovery" (Salmon, 14).
-Negative justifications are used to disprove arguments while positive justifications are used to prove arguments
-Genetic fallacy is when statements are wrongly treated in the context of discovery as if they belonged in the context of justification. For example, The Nazis condemned the theory of relativity because Einstein, its originator, was a Jew.
-Logic cannot provide a description of actual thought process, that is psychology's domain
-Logic provides tools for making sound evaluation of inferences
-After the inferences have been made it can be transformed into an argument and then be analyzed for logical correctness
-Accepting incorrect inferences is illogical