Hendrik Wagenvoort maintained that "caerimoniae" were originally the secret ritual instructions laid down by Numa, which are described as "statae et sollemnes", "established and solemn." These were interpreted and supervised by the College of Pontiffs, flamens, "rex sacrorum" and the Vestals. Later, "caerimoniae" might refer also to other rituals, including foreign cults. These prescribed rites "unite the inner subject with the external religious object", binding human and divine realms. The historian Valerius Maximus makes clear that the "caerimoniae" require those performing them to attain a particular mental-spiritual state ("animus", "intention"), and emphasizes the importance of "caerimoniae" in the dedication and first sentence of his work. In Valerius's version of the Gallic siege of Rome, the Vestals and the Flamen Quirinalis rescue Rome's sacred objects ("sacra") by taking them to Caere; thus preserved, the rites take their name from the place. Although this etymology makes a meaningful narrative connection for Valerius, it is unlikely to be correct in terms of modern scientific linguistics. An Etruscan origin has sometimes been proposed. Wagenvoort thought that "caerimonia" derived from "caerus", "dark" in the sense of "hidden", hence meaning "darknesses, secrets."