Tasso stresses that the discovery of the Holy Lance, hidden in Antioch, was made possible by a vision of angels that was "unlike" the images produced by phantoms and/or devils. There was a need to be able to recognize the true manifestations of the Divine by distinguishing them from their dangerous devilish imitations [therefore "divine touch-screen," where you do "touch" but it is anyway a "screen"]. This is the discernment of spirits that in the 16th century was brought back to attention by St Ignace de Loyola, the founder of Jesuits, who retrieved the ancient teachings of the Church Fathers.
A precious art that - just to insert a reference to the contemporary situation, once in a while - in the Catholic Church has nearly gone lost after the Sixties, when they thought it was smarter to resort to second-hand psychology and third-rate sociology. Discernment still plays a role in the Orthodox Churches, though.
To be continued . . .