[Meaning one who is] discriminating, diagnosing.
"Heraiskos actually had a natural talent for distinguishing between religious statues that were animated and those that were not. For as soon as he looked at one his heart was struck by a sensation of the divine and he gave a start in his body and his soul, as though seized by the god. If he was not moved in such a fashion then the statue was soulless and had no share of divine inspiration. In this way he distinguished the secret statue of Aion which the Alexandrians worshipped as being possessed by the god, who was both Osiris and Adonis at the same time according to some mystical union. There was also something in Heraiskos' nature that rejected defilements of nature. For instance, if he heard any unclean woman speaking, no matter where or how, he immediately got a headache, and this was taken as a sign that she was menstruating. Even his birth had something mystical about it: he is said to have issued from his mother holding the shushing finger up to his lips, just as the Egyptians portray Oros and Helios. As a result, since the finger was fused to his lips, he needed surgery, and he went through life with a scar on his lip."[1]