is this an example of an invalid argument
All crows are black
John is black
Therefor, John is a crow.
is this an example of a unsound argument
All dogs are black
Lassie is a dog
Lassie is a cat
Please tell me if this is right.
You're right for both arguments.
The premise for the first statement is correct. But obviously the conclusion is wrong -- making the argument invalid.
The premise for the second argument is not correct. Therefore it is both invalid and unsound.
To determine whether an argument is valid or invalid, you need to examine the logical structure of the argument. In a valid argument, the conclusion follows logically from the premises. If an argument is invalid, it means that the conclusion does not necessarily follow from the premises, even if the premises are true.
In the first argument, the premises state that all crows are black and John is black. However, the conclusion that John is a crow does not necessarily follow from these premises. There could be other reasons why John is black, so the argument is invalid.
In the second argument, the premises state that all dogs are black and Lassie is a dog. However, the conclusion that Lassie is a cat contradicts the premises, making the argument invalid as well as unsound. An argument is unsound if it is both invalid and has at least one false premise. In this case, the premise stating that all dogs are black is false.
In summary, the first argument is invalid, and the second argument is both invalid and unsound due to a false premise.