 Bayesians focus not only on likelihoods but also on priors and posteriors, and in their eyes the crucial significance of the inequality \(\eqref{likelihoods}\) is that it leads to a ratio \(P^+(D)/P^+(\neg D)\) of posteriors that is much larger than the ratio \(P(D)/P(\neg D)\) of the priors. Whether belief in a designer is rational depends ultimately on the priors as well, but unless those values dramatically favour \(\neg D\) over \(D\) in that \(P(\neg D)\gg P(D)\), the posteriors will favour design in that \(P^+(D)&gt; P^+(\neg D)\). Bayesian proponents of the argument from fine-tuning for design conclude that our degree of belief in the existence of some divine designer should be greater than \(1/2\) in view of the fact that there is life, given the required fine-tuning.