PHI 1101 Lecture Notes - Lecture 6: Modus Ponens, Thanetian, Modus Tollens

• School: University of Ottawa
• Department: Philosophy
• Course: PHI 1101
• Professor: Mark Brown

Document Summary

An argument intended to provide logically conclusive support for its conclusion. The defining characteristic of a deductive argument is that it is valid or invalid. A deductive argument is intended to provide conclusive support for its conclusion. The structure of some arguments is deductive. When arguments structured this way are good, they guarantee their conclusion. In each case, if the premise offered really are true, then the conclusion must also be true, and we can therefore describe that the argument as being valid. Note: you have to look as the structure of the argument. Accordingly, if an argument has a combination of false premises and a false conclusion, it is still valid. Arguments that are valid can be described as having: If an argument has a true premise and a false conclusion then it is invalid. Chapter 3, page 33: invalid, invalid, valid. 8 valid argument forms: modus ponens (mp)