PHI 1101 Lecture Notes - Lecture 6: Deductive Reasoning

• School: University of Ottawa
• Department: Philosophy
• Course: PHI 1101
• Professor: Devin Shaw

Document Summary

When an argument shows that its conclusion is worth accepting. We say that the argument is good An argument intended to provide probable conclusive support for its conclusion. A deductive argument is intended to provide conclusive support for its conclusion. Example: john is taller than amy, amy is taller than melissa. Deductive arguments that succeed in providing conclusive support for its conclusion is said to be valid. If a deductive argument fails to provide conclusive support it is seen as invalid. A deductively valid argument with true premises is said to be sound. Valid arguments, all of whose premises are true, are called sound. Issues to consider: are premises true, do those premises lead to this conclusion. Example: pigs have wings, any animal with wings can fly, so, pigs can fly 99% of students in the course will pass. This is not a deductive argument because the argument is invalid.