Key Terms
Bertrand Russell put it bluntly
Once a question gets a definitive answer, it stops being philosophy and becomes a science.
Dialectic
A structured dialogue between two or more people aimed at getting closer to the truth — not winning.
Hypothesis
A proposed explanation for an observed phenomenon.
Testing uses conditionals (if-then statements)
"If X, then Y."
Law of Noncontradiction
Contradictory statements cannot both be true in the same sense at the same time.
Law of the Excluded Middle
For any statement, either that statement is true or its negation is true. No third option.
Conditional
An if-then statement that expresses the logical relationship between two propositions.
Example
Arguing abortion is murder by assuming in a premise that a fetus is a person — when whether a fetus is a person is exact
Sufficient condition
The antecedent (X). If X is true, Y is guaranteed.
Necessary condition
The consequent (Y). Y must be true whenever X is true.
Counterexample
A single case that proves a statement false or an argument invalid. Universal affirmative statement: "All A are B"; logi
Universal affirmative statement
"All A are B." Claims every member of group A is also in group B.
To disprove a universal statement
Find ONE counterexample — one A that is not a B.
Argument
A set of reasons (premises) offered in support of a conclusion. Premise: a reason or piece of evidence offered to suppor
Conclusion indicator words
Therefore, hence, so, thus, consequently, accordingly, as a result, it follows that, we can conclude, it must be that