At present a broad consensus may be discerned on Aquinas' ‘five ways' for proving the existence of God: either he is responding to atheism per se by means of five rational arguments, or he is not responding to any formal denial of God's existence. Both of these approaches ignore the two specific objections Aquinas raises prior to the five ways: evil is incompatible with the existence of an infinite goodness (the first objection), and the world does not require an external explanation (the second objection). While some have speculated on the structural significance of the second objection, the first has been universally regarded as irrelevant. This, I argue, is an oversight; Aquinas' first objection (from evil) is central to the quinque viae. Seen in this light, while Aquinas' five ways are not responses to atheism per se, they do address, and ultimately subvert, a specific form of disbelief.