PHL201H1 Lecture 4: Lecture 4
Document Summary
A good deductive arguments must be a valid argument. Valid: premises if true guarantee the truth of the conclusion. If the premises are true there is no way for the conclusion to be false. This does not say anything about whether the premises or the conclusion are actually true. If statement is sattisfied by the first statement, then the then part is true which will be the conclusion. Does not matter whether the then part is true or not, say ottawa is not a capital of canada will still be true. There is a possible situation that grasses are not green and dandelions are not yellow (need to rule out all impossible situations, thus need to add premises that grass is green and dandelions are yellow) An argument is sound if it is valid and all of its premises are true -- the gold standard of arguments. The conclusion is guaranteed to be true.
