In Plato’s Euthyphro, Euthyphro proposes to analyse the pious as that which is beloved of the gods. In the most widely discussed argument of the dialogue, Socrates tries to show that Euthyphro’s analysis fails. The argument crucially involves an ingenious use of the explanatory connective ‘because’. This paper presents a detailed reconstruction and defence of the argument. It starts with a rigorous analysis of its logical form, explains and justifies its premises, and closes with a defence of the argument against (...) the strongest common objection. (shrink)