 A precise version of the argument can be formulated as follows: Choose some proposition about a future act that you think you will do freely, if any act is free. Suppose, for example, that the telephone will ring at 9 am tomorrow and you will either answer it or you will not. So it is either true that you will answer the phone at 9 am tomorrow or it is true that you will not answer the phone at 9 am tomorrow. The Law of Excluded Middle rules out any other alternative. Let T abbreviate the proposition that you will answer the phone tomorrow morning at 9, and let us suppose that T is true. (If not-T is true instead, simply substitute not-T in the argument below).