Gil Renberg has done the field an incredible service with the publication of this monumental and far-reaching study. In the preface, Renberg states that one of his primary goals is to offer scholars a single resource for ancient incubation across the Near Eastern and Classical worlds (XVI). He has done precisely this with an exhaustive treatment of textual and archaeological evidence for incubation, including quotations of relevant texts in both the original language and in translation, alongside complete publication histories.

Beyond Renberg’s desire that his book serve as a reference, he is concerned with two key issues: locations and types of incubation. First, he aims not merely to compile all the sites at which scholars have suggested incubation took place, but to evaluate the evidence for each. To that end, he offers conclusions about whether the ancient evidence is sufficient to determine conclusively that any particular site was in fact an incubation sanctuary. Second, Renberg argues that we must distinguish between two distinct types of incubation—divinatory and therapeutic—that were practiced in the ancient world, suggesting that the former was both earlier and more widespread than the latter.