Herodotus speaks of the Chaldaeans as "priests;" Strabo says that they were "philosophers," who occupied themselves principally in astronomy.

The latter writer mentions that they were divided into sects, who differed one from another in their doctrines.

He gives the names of several Chaldaeans whom the Greek mathematicians were in the habit of quoting.

Among them is a Seleucus, who by his name should be a Greek.
From these various authorities we may assume that there was in Babylon, as in Egypt, and in later Persia, a distinct priest class, which enjoyed high consideration.

It was not, strictly speaking, a caste.