Recently, the Intelligent Design (ID) movement has challenged the claim of many in the scientific establishment that nature gives no empirical signs of having been deliberately designed. In particular, ID arguments in biology dispute the notion that neo-Darwinian evolution is the only viable scientific explanation of the origin of biological novelty, arguing that there are telltale signs of the activity of intelligence which can be recognized and studied empirically. In recent years, a number of Catholic philosophers, theologians, and scientists have expressed opposition to ID. Some of these critics claim that there is a conflict between the philosophy of St. Thomas Aquinas and that of the ID movement, and even an affinity between Aquinas’s ideas and theistic Darwinism. We consider six such criticisms and find each wanting.