An extract from Rules for the Discernment of Spirits in The Spiritual Exercises of St Ignatius of Loyola:
"315 Rule 3: If a cause precedes, both the good angel and the evil spirit can give consolation to a soul, but for a quite different purpose.
"325-327: The enemy conducts himself as a woman.... Our enemy may also be compared in his manner of acting to a false lover.... The conduct of our enemy may also be compared to the tactics of a (military) leader.
"332: It is a mark of the evil spirit to assume the appearance of an angel of light. He begins by suggesting thoughts that are suited to a devout soul, and ends by suggesting his own. For example, he will suggest holy and pious thoughts that are wholly in conformity with the sanctity of the soul. Afterwards, he will endeavour little by little to end by drawing the soul into his hidden snares and evil designs."
An extract from Chapters 6 and 7 in Fr Thomas Green's book, Weeds Among the Wheat:
"Like a woman... Ignatius clearly does not mean every woman here... The point, I take it, is that a woman generally cannot rely on physical strength, on brute force, to get her way. ... women, and men who are physically weaker, have to rely on their wits ... to tyrannize or outwit others.... Satan cannot overcome those who belong to Jesus Christ by brute force. He has to depend on threats and subtle pressures and... is ruthless when we are timid and cowardly when we are firm.
"... next ... a false lover ... 'seeks to remain hidden and does not want to be discovered.' When he (or she) seeks to seduce another, 'he wants his words and solicitations kept secret (#326). The false lover will persuade the girl not to tell her father or brothers, since they are old-fashioned and narrow-minded. Similarly, the devil will urge the sould not to confide in a confessor or a director or a superior; they are too busy, too strict, too lax, too modern or too old-fashioned. "For he knows that he cannot succeed in his evil undertaking, once his evident deceits have been revealed."
"Finally ... a military commander ... studies the whole situation, and probes to discover the physical and psychological weaknesses of his adversary. Then he attacks 'at the weakest point.' ... our angelic enemy... studies our character and searches for our Achilles' heel... How important it is, then, that we know ourselves and our own weaknesses. Once we know them, we can bring them to the Lord for healing, and the devil's advantage will be lost.
"... the evil spirit is the father of lies (John 8:44). His shrewdness is unprincipled and thus he has no scruples about mimicking the voice of God when it suits his purposes. When he cannot deceive or block the committed soul by means of desolation, he seeks to imitate the Lord's way of speaking and acting.
"... one essential, consoling truth: However wily and deceitful the evil spirit may be, he can never perfectly mimic the consolations of God. He can produce ecstasies and visions; and he can foster, for his own ends, the noblest of humanitarian projects and the most intense apostolic zeal, but the tail of the snake will always appear when the devil is in the picture.
"... one of the surest signs of interior maturity which I have found is a healthy mistrust of even our best motivations. St John of the Cross tells us that the more we grow in Christ, and the greater our potential for good in the church, the more the devil will be working to spoil the harvest. It makes sense... if you were the devil... you would not wast much energy on half-hearted or mediocre souls ... This is why our popes and bishops and civil leaders command special attention in our eucharistic prayers.
"... St Ignatius treats it in rules 5 and 6 of the second week... 'We must carefully observe the whole course of our thoughts. If the beginning and middle and end... are wholly good and directed to what is entirely right, it is a sign that they are from the good angel. But the course of thoughts suggested to us may terminate in something evil, or distracting, or less good than the soul had formerly proposed to do. Again, it may end in what weakens the soul, or disquiets it; or by destroying the peace, tranquillity and quiet which it had been before, it may cause disturbance to the soul (#333).'
"The important thing ... is that we learn from our experience. The devil can be a treacherous adversary; but in the end the poor fellow, quite against his will, also proves to be one of our best teachers, a real instrument of our sanctification!"