This idea of diabolic agency in mental disease had grown luxuriantly in all the Oriental sacred literatures.

The heathen gods became devils, and the marvels related of them were supposed to be effected by diabolic agency.

When first he hears Horatio's story, he seems to incline to the belief that it must be the work of some diabolic agency:

Some said that Michel had been permitted to save the child by a diabolic agency which had failed him when he sought to save himself.

What if she had sinned, and trafficked with diabolic agencies, in trying to read the future?