  The first argument for moral liberty parallels Reid's response to external world skepticism (see 3.5 Responding to Skepticism about the External World, above). Reid claims that the belief that we are endowed with power to produce our own actions is a first principle and then employs his general form of defense of first principles in order to argue that it must be so. We naturally and non-inferentially believe ourselves to be endowed with power since various activities in which we engage would make no sense if we did not believe ourselves to be endowed with power. For instance, he claims that the activity of deliberating, of weighing reasons for and against various possible actions, proceeds under the assumption that we have power; if we didn't believe that, he thinks, then we would not bother deliberating.