As soon as religion began to lose its purity, it degenerated very fast; and, instead of a reverential awe and pleasing sense of duty, there succeeded a fearful gloom and unnatural horror, which were continually augmented as superstition increased. Men repaired in the first ages either to the lonely summits of mountains, or else to caverns in the rocks, and hollows in the bosom of the earth; which they thought were the residence of their Gods. At the entrance of these they raised their altars and performed their vows. Porphyry takes notice how much this mode of worship prevailed among the first nations upon the earth: [661]Σπηλαια τοινυν και αντρα των παλαιοτατων, πριν και ναους επινοησαι, θεοις αφοσιουντων και εν Κρητῃ μεν Κουρητων Διι, εν Αρκαδιᾳ δε Σεληνῃ, και Πανι εν Λυκειῳ και εν Ναξῳ Διονυσῳ. When in process of time they began to erect temples, they were still determined in their situation by the vicinity of these objects, which they comprehended within the limits of the sacred inclosure. These melancholy recesses were esteemed the places of the highest sanctity: and so greatly did this notion prevail, that, in aftertimes, when this practice had ceased, still the innermost part of the temple was denominated the _cavern_. Hence the Scholiast upon Lycophron interprets the words παρ' αντρα in the poet, [662]Τους εσωτατους τοπους του ναου. _The cavern is the innermost place of the temple_. Pausanias, speaking of a cavern in Phocis, says, that it was particularly sacred to Aphrodite. [663]Αφροδιτη δ' εχει εν σπηλαιῳ τιμας. _In this cavern divine honours were paid to Aphrodite._ Parnassus was rendered holy for nothing more than for these unpromising circumstances. Ἱεροπρεπης ὁ Παρνασσος, εχων αντρα τε και αλλα χωρια τιμωμενα τε, και, ἁγιστευομενα.[664] _The mountain of Parnassus is a place of great reverence; having many caverns, and other detached spots, highly honoured and sanctified_. At Tænarus was a temple with a fearful aperture, through which it was fabled that Hercules dragged to light the dog of hell. The cave itself seems to have been the temple; for it is said, [665]Επι τῃ ακρᾳ Ναος εικασμενος σπηλαιῳ. _Upon the top of the promontory stands a temple, in appearance like a cavern_. The situation of Delphi seems to have been determined on account of a mighty chasm in the hill, [666]οντος χασματος εν τῳ τοπῳ: and Apollo is said to have chosen it for an oracular shrine, on account of the effluvia which from thence proceeded. [667]Ut vidit Pæan vastos telluris hiatus Divinam spirare fidem, ventosque loquaces Exhalare solum, sacris se condidit antris, Incubuitque adyto: vates ibi factus Apollo.