After affirming God’s existence since God himself says he exists (Exod 3:14), Thomas shares five ways that show God’s existence. In the context of the Summa, Thomas here aims to establish the existence of his object of study, which in this case is God. Here he follows a standard procedure in pre-modern scientific study to first establish the existence of a subject before characterizing how it exists or its essence. Drs. Ian Clary and Wyatt Graham discussed the First Way in some detail in their last episode as well.
Into Theology 66: Thomas Aquinas on the Five Ways (ST I.Q2)
Episode No. 001