“Pausanias writes that four hundred years after the battle of Marathon, there were still heard in the place where it was fought, the neighing of horses and the shouts of shadowy soldiers. Supposing that the spectres of the slaughtered soldiers were their genuine spirits, they looked like “shadows”, not materialized men.
Who, then, or what, produced the neighing of horses? Equine “spirits”? And if it be pronounced untrue that horses have spirits – which assuredly no one among zoologists, physiologists or psychologists, or even spiritualists, can either prove or disprove – then must we take it for granted that it was the “immortal souls” of men which produced the neighing at Marathon to make the historical battle scene more vivid and dramatic?
The phantoms of dogs, cats, and various other animals have been repeatedly seen, and the world-wide testimony is as trustworthy upon this point as that with respect to human apparitions. Who or what personates, if we are allowed such an expression, the ghosts of departed animals? Is it , again, human spirits?
As the matter now stands, there is no side issue; we have either to admit that animals have surviving spirits and souls as well as ourselves, or hold with Porphyry that there are in the invisible world a kind of tricky and malicious demons, intermediary beings between living men and “gods”, spirits that delight in appearing under every imaginable shape, beginning with the human form, and ending with those of multifarious animals.”
H. P. Blavatsky