 [I]n order for me to think that I am thinking, two thoughts are needed, with one reflecting on the other—the later, current one on the previous, earlier one—so that in order for the first thought, by which the mind is aware, to be placed before the mind, the second thought, by which the mind is aware, is of the first thought. Or, in short, the first thought will be the end or object of the second; the second will be the action of the mind whereby it is directed to the first thought. But it is a contradiction that both should occur by a single action… (84)