Besides Cassian, John Chrysostom is the Church Father who is most often appealed to as the representative of a 'pious lie' tradition. When we look at Chrysostom, however, we find many of the same ambiguities present in Cassian, and perhaps more.
Chrysostom's On the Priesthood opens with an autobiographical story of Chrysostom's relationship with one of his early friends. This friend was more religious than Chrysostom himself, for young John was tangled with the desires of the world, but their friendship held, and as John became more serious and mature, the friend, whose name was Basil, began to spend much more time with John, and proposed that they together share a house, priests together, with the object of growing in the spiritual life.
John still had a mother, however, and his mother, hearing of the plan, took him aside. Weeping profusely, she reminded him that she no longer had his father to lean on, and begged him to remain with her for as long as she lived, and not leave her alone to the trials of widowhood. John communicated this to Basil, but Basil insisted that they still should join together and form a religious community. At this time they both heard word that they were likely to be advanced to the episcopate. John was very alarmed at this rumor, neither feeling ready nor regarding himself as worthy of the honor. Basil came to him and said that whatever John decided, Basil would follow him in the endeavor. John, however, realized that he could not deprive the Church of a bishop of Basil's qualities, said that they should postpone the decision, in such terms as to encourage Basil to think that they would both accept the episcopacy. When the person came to raise them the episcopate, John hid himself, and Basil reluctantly accepted the honor, particularly since some bystanders made him think that John had already accepted it. Basil was distraught when he learned the truth, but John rejoiced at his friend's honor, praising God that his plan had worked. Basil, seeing this, realized that this had been John's plan all along, and was even more grieved.
Basil remonstrated with John, saying that he would now have the shame of having to hide the fact that he had been tricked. Many people accused John of vainglory and arrogance because he hid from receiving episcopal honors, but Basil could not respond to the accusation, because everyone thought he was in on it: he could never get anyone to believe that he and John, such close friends, did not know all the details of each other's schemes, and, that he could not bear to suggest that their friendship had been so weak that John kept Basil from knowing his intent. John took advantage of the openness of their friendship. Nonetheless, he did not demand an apology or that John should justify his deception, but only that John should tell him how he could possibly answer the accusations against John.
John, however, was unphased, and insisted that he could justify himself on all counts. What wrong had John actually done? He had deceived Basil, but for Basil's own good and the good of others. The evil of deception is not absolute; it depends on the intentions of those who practice it. Generals are esteemed for their capacity to deceive, and in war and peace alike deceptions have been the saving of many lives.
Basil dismissed this, pointing out that he was not an enemy.
Ah, replied John, but deception does not always only benefit the deceiver. Physicians sometimes must trick their patients to get them to take their medicine. Likewise, St. Paul attracted the attention of Jews by circumcising Timothy, even though neither were under the law. Such deception is not even really accurately called deception, because it is more like a prudent management of the situation, a form of cleverness. That man is a deceiver who makes unjust use of such practices; the one who makes salutary use of them is in a different category altogether. The benefits Basil received were those of St. Peter, whom Christ told to show his love not by fasts, vigils, and the like, but by tending Christ's sheep.
But what of John, then, who claims to love Christ, the proper expression of which is tending His sheep, but who fled the honor? That was due to John's inability to fulfill the function. John then argues that Basil, on the other hand, was ready and suitable for fulfilling the office. This, of course, serves as the framework for the rest of the discussion, which is about the high standards that should be expected of those admitted to the priesthood, and especially to the episcopacy.
This, then, is one of the major texts people sometimes appeal to in order to make a place for lying in piety. But it is clear enough that this text will only get one so far. We have no reason to think that John lied outright to Basil; we don't have a precise account of what he said, but we don't have any reason to think it was a lie. When Basil accuses him of deceit, what he accuses him of is not saying false things but withholding information, knowing that Basil would assume that John had told him everything. And it is this that John is defending, and even goes so far as to say is not really deceit at all. And there is nothing in this that is directly contrary to the tradition that it is always wrong to lie; what Chrysostom describes is not clearly a lie at all. Indeed, he pretty much says this himself.
the second passage in Chrysostom that is sometimes adduced on this subject is Chrysostom's influential discussion of the confrontation between Peter and Paul, as described by Paul in the epistle to the Galatians. Chrysostom, like a number of Fathers, had difficulty thinking of Peter as quite so obtuse about God's plan as he might seem on bare literal reading, particularly given that he had had it directly from God, and had difficulty reconciling Paul's behavior in this situation with his circumcision of Timothy, so Chrysostom (and others) suggested that there were indications in the text that it was in fact an elaborate set-up by Peter and Paul (a simulated confrontation). Peter had begun to accept Gentile ways as a way of welcoming the Gentiles, but he was sharply criticized for this by Jewish Christians, who were extremely upset by it. Thus, said Chrysostom (I will be giving only a rough summary), Peter reverted to Jewish Christian ways, expecting Paul to jump in and raise a ruckus. This Paul did, seeing exactly what Peter was about, and sharply and publically criticized Peter; Peter in turn meekly accepted the rebuke as an example to the Jewish Christians. Thus Peter and Paul were able to make the point without alienating the Jewish Christians from Peter: the new situation could be presented to them as a way to keep peace with the community at large and not as Peter's own willful choice, while, at the same time, Peter's acceptance of the rebuke provided an example for the Church at large to follow and gave a certain amount of authority to Paul. The circumcision of Timothy was a similar ruse on the part of Paul, a concession unnecessary in itself but valuable for not alienating Jewish believers and the Jewish community at large.
Now it is notable that this elaborate management of the situation involves no outright falsehood, either: nothing either Peter or Paul says is false, and the only thing that can remotely be called dissimulation is the fact that Peter accedes to the demands of the Jewish Christians not because he agrees with them but because he knows that it will give Paul an opportunity to make an important point. It's an elaborate teaching exercise. Some Fathers, most notably Augustine, were uncomfortable with the whole notion of the ruse, and Augustine and Jerome had one of their first fights over it, Jerome insisting that the ruse interpretation was the more pious and reasonable interpretation and Augustine insisting that it was more pious and reasonable just to say that Peter made a mistake and Paul corrected him. But however uncomfortable Augustine may have been with it, the ruse, should one choose to accept that interpretation, doesn't fall under any later definition of lying, or even Augustine's own definition of lying. The worry is not that Peter and Paul lied in any proper sense but that deception, even with good intention, is dangerous business for the soul, and the difference between the Fathers on this point is simply over whether it was too dangerous.
We find, then, much the situation with Chrysostom that we found with Cassian: we must avoid naive reading because the 'lying' involved in these cases doesn't map onto post-Augustinian accounts of lying in a straightforward way. To the extent that 'lies' are talked about at all in this context, the Fathers are usually using the term loosely, and even then they often show recognition of the complexities of this loose usage, as with Chrysostom's claim that his deception of Basil shouldn't even really be called a deception. There are still ambiguities about how far Chrysostom thinks one can go, but it's important to note that they are ambiguities: nothing Chrysostom says is outright inconsistent with the post-Augustinian tradition that lying is always wrong, and trying to make them inconsistent requires a considerable amount of eisegesis.