Deductive Reasoning 101
What is an example of deductive reasoning?
Premise 1: It is cold outside.
Premise 2: I need to wear a jacket when it is cold outside to keep warm.
Conclusion: I will wear my jacket outside in the cold.
Give an example of conditional (propositional) reasoning.
Premise 1: the patient is a diabetic.
Premise 2: high blood pressure can cause abdominal issues.
Conclusion: the patient has high blood pressure.
*Is this Invalid or Valid reasoning? This is technically invalid, but only because there is not enough supporting evidence to factually claim this to be true.
When we affirm the antecedent, we say the "if" part is true. What type of conclusion does this lead us to?
To deny is to conclude that a statement made is false or invalid.
TRUE
What are the two types of deductive reasoning?
Conditional (propositional) reasoning and Syllogism
What is Syllogism?
When we affirm the consequent, we say the "then" part is true. What type of conclusion does this lead us to?
invalid conclusion
The antecedent is when the consequence (the "then" part) is true.
FALSE - this is the consequent!
What is a Heuristic?
A general strategy used in deductive reasoning.
Example: "I have a good feeling about it" is not the same as "this is absolutely true" in deductive reasoning. Using Heuristics helps us determine the validity.
Give an example of Syllogism.
Premise 1: some psychology majors are caring people.
Premise 2: some friendly people have concerns about ethics in true crime.
Conclusion: therefore, some psychology majors are concerned about the ethics in true crime.
*Is this Invalid or Valid reasoning? This example is not invalid nor valid, its indeterminate.
When we deny the antecedent, we say the "if" part is false. What type of conclusion does this lead us to?
invalid conclusion
The consequent is when the statement (the "if" part) is true.
FALSE - this is the antecedent!
When we deny the consequent, we say the "then" part is false. What type of conclusion does this lead us to?
valid conclusion
We can affirm/deny the antecedent/consequent is true in a conditional reasoning statement.
TRUE - this is the purpose of the terminology!