Tertullian

“ These were the ingenious arts of “spiritual wickednesses,” [1] wherewith we also, my brethren, may fairly expect to have “to wrestle,” as necessary for faith, that the elect may be made manifest, (and) that the reprobate may be discovered. And therefore they possess influence, and a facility in thinking out and fabricating [2] errors, which ought not to be wondered at as if it were a difficult and inexplicable process, seeing that in profane writings also an example comes ready to hand of a similar facility. ”