8. True/False Review and Chapter Summary Use your knowledge of argument forms and the counterexample method to determine which, if any, of the following statements are true. Check all that apply. O It is possible to give a counterexample to a valid argument that has false premises and a false conclusion. O Each argument is a substitution instance of one, and only one, argument form. A substitution instance is a representation of the logical structure of an argument using form words and letters. A counterexample is an effective way to raise an objection to faulty deductive reasoning. The counterexample method is useful only for deductive arguments. A counterexample can be used to show an argument's invalidity because it offers a set of truth values that would be impossible if an argument form were valid. O Every deductive argument is valid or invalid because of its form. A successful counterexample will have all true premises and a true conclusion. A counterexample is a substitution instance with true premises and a false conclusion. O Every substitution instance of a valid argument form will itself be valid. An argument may be a substitution instance of more than one argument form. The counterexample method is useful only for proving the invalidity, not the validity, of an argument. When you are extracting an argument form from an argument, the form words are replaced with letters and the content words are left alone. Some invalid arguments have valid argument forms. A counterexample may have false premises and a false conclusion