The purpose of question 75 (LXXV) is to sort out how the soul relates to the body. According to Thomas Aquinas, theologians have put a great deal of thought into how the soul relates to human beings overall. Yet Aquinas feels that the relationship between the literal body and the soul has been neglected. With question 75 in Summa Theologica, Aquinas tries to thoroughly investigate the properties of the soul and its link to the body.
In the first objection, Aquinas figures out if the soul is a body. In the opening sentence of objection 1, Aquinas enunciates a succinct answer. He states, “It would seem that the soul is a body.” Aquinas then supplies an explanation for his answer. The explanation revolves around Aquinas’s idea of movement. Aquinas calls the soul “the moving principle of the body.” However, the soul isn’t “moved unless moved.” The soul is a “mover moved.” It’s something that can elicit motion because of external motion. As Aquinas says elsewhere in the text, “[E]verything which is in motion must be moved by something else.”
Thus, the soul is subject to the same conditions as the body. Neither the body nor the soul is dormant. They’re active entities that can influence and animate in part because they're influenced and animated by their surroundings and environments. If the body is defined as a mover that’s moved, and if the soul can be defined as a mover that’s moved, then Aquinas, in objection 1, is content with concluding that the soul is a body.