table of contents

valid

2023-06-29

an argument is valid iff its not possible for its conclusion to be false when its premises are true.

otherwise, a deductive argument is said to be invalid.

a valid argument can have false premises; and it can have a false conclusion. but if a valid argument has all true premises, then it must have a true conclusion.

im confused:

if one premise is false, doesnt this automatically cause a contradiction? because its not true in the first place so it satisfies "not all premises can be true at the same time", and since a false premise causes a contradiction, doesnt this make the argument automatically valid?

im guessing i have the wrong definition of a "false premise"?

is a false premise just something thats not a tautology?