Basilidean cosmology described reality as organized into a great many successive ranks or heavens, ancient sources most often cite the number three hundred sixty five, each populated by its own ruling powers descending in a hierarchy from a wholly transcendent, unknowable supreme being down toward the material world familiar to ordinary human experience. At the head of this structure Basilides placed a being he named Abraxas, whose name was constructed so that the numerical values of its Greek letters summed to three hundred sixty five, tying the name arithmetically to the full sequence of heavens and, by extension, to the days of the solar year. The school taught a threefold division of existence, material, intellectual, and spiritual, echoing the kind of tiered anthropology found in other Gnostic systems of the period, including the roughly contemporary Valentinian school, though the two traditions differed in many particulars of their cosmological detail. Basilidean teaching reportedly also made use of two paired allegorical statues, one male and one female, as part of its symbolic instruction, though the exact role these images played in Basilidean ritual or teaching is known to modern historians only through the brief and often hostile summaries left by the church writers who opposed the sect, rather than through any surviving Basilidean text of its own.