Sye explains presuppositionalism: start with the presupposition that God exists and his Word is true; all reasoning depends on God; the 'circle' is virtuous, not vicious

The classical objection to presup is that it is circular — you can't start with God to prove God. Sye responds that all reasoning is circular, but the presup circle is virtuous because it appeals to an omniscient God as the foundation of rationality. If an unbeliever is reasoned to God using autonomous reason, they can say 'I got there without God' — which denies Romans 11:36 ('from him, through him, to him are all things'). Evidentialists grant the unbeliever autonomous reason and then try to conclude God — but then God is not really the ground of that reasoning. Sye's formula: 'God is not a God we reason to; He is the God we cannot reason without.'