An argument with a false conclusion must be invalid.
An argument with false premises must be invalid.
An argument with true premises and a false conclusion must be invalid.
An argument with true premises and a true conclusion cannot be invalid.
(1) If pigs are animals, then pigs can fly. (2) Pigs can fly. (3) So pigs are animals.
(1) If pigs are animals, then pigs can fly. (2) Pigs are animals. (3) So pigs can fly.
(1) Most insects are organisms with wings. (2) Most organisms with wings have more than two legs. (3) So most insects have more than two legs.
Suppose an argument has true premises and a true conclusion. Then:
Suppose an argument is valid and the conclusion is true. Then:
(1) Either Tom is sad or Tom is not sad. (2) Tom is not sad. (3) So Tom is happy.
(1) Chemical E4786 causes cancer in human beings. (2) Bread from company X includes E4786. (3) So company X should not have put E4786 in bread.
(1) Every burger contains meat. (2) Meat contains protein. (3) So every burger contains protein.
"I like eating meat. So eating meat is not wrong." Find a missing premise that makes the argument valid.