Abstract

The thirteenth century Dominican monk Thomas Aquinas is famous for his five succinct arguments for the existence of God. These arguments have come to be known as the Five Ways. This work is an attempt to defend the soundness of the second of these Five Ways referred to as the Second Way. This argument is also known as the First Cause argument or the argument from efficient causality. ;First, the argument is set in both its historical and philosophical context. It is argued that the full force of the Second Way can only be appreciated once the philosophical antecedents of the argument are unpacked. These philosophical antecedents include the Aristotelian notions of act and potency, form and matter and causality and the contribution by Thomas of the essence/existence distinction and the primacy of esse. ;Second, the argument is defended against objections to theistic arguments in general. The objections are from the attacks on natural theology stemming from fideism , Presuppositionalism , Logical Positivism , and skepticism . ;Third, the argument is defended against objections to efficient causality arguments as such. The objections are whether causality can be known , whether causality applies to God , whether the universe could be uncaused and whether the universe could be self-caused . ;Fourth, the argument is defended against specific objections to the Second Way in particular. These objections are whether an infinite regress is possible, whether the Second Way commits the fallacy of composition, whether the Second Way commits the quantifier shift fallacy, whether Thomas' robust theism follows from the premises, whether the first cause is God, whether there is only one God, whether God is good, and whether the Second Way is predicated upon on obsolete philosophical system