The philosopher Porphyry (3rd–4th century CE) gives an account of the origins of the Mysteries in his work "De antro nympharum" (The Cave of the Nymphs). Citing Eubulus as his source, Porphyry writes that the original temple of Mithras was a natural cave, containing fountains, which Zoroaster found in the mountains of Persia. To Zoroaster, this cave was an image of the whole world, so he consecrated it to Mithras, the creator of the world. Later in the same work, Porphyry links Mithras and the bull with planets and star-signs: Mithras himself is associated with the sign of Aries and the planet Mars, while the bull is associated with Venus.