On June 28, 2015, Bishop Williamson publicly stated that the new mass is bad but that people should use their own judgment whether it is good for them. Here are his words:

Do whatever you need to nourish your Faith. ... I would not say that every single person must stay away from every single novus ordo mass. ... It is case by case. ... Therefore, the essential principle is: do whatever you need to keep the Faith. ... You make your own judgments. ... I’ve got to use my own mind in my own circumstances. ... I would not say every single person must stay away from every single novus ordo mass, if they can trust their own judgment, that attending this mass would do them more good than harm spiritually; but it does harm in itself. ... You must work it out for yourselves.¹

This is the heresy of Situation Ethics! Bishop Williamson is telling people that they should “trust their own judgment” whether the new mass is good for them, even though it is evil and “does harm in itself”!

In 1952, Pope Pius XII condemned this pernicious method of making decisions:

The distinctive mark of this morality [i.e., Situation Ethics] is that it is in fact in no way based on universal moral laws, for instance, on the Ten Commandments, but on the real and concrete conditions or circumstances in which one must act, and according to which the individual conscience has to judge and choose. This state of things is unique and valid only once for each human action. This is why the supporters of this ethics affirm that the decision of one’s conscience cannot be commanded by universal ideas, principles, and laws...

Acts of the Apostolic See, 1952, pp 413-419 (emphasis added).

Pope Pius XII is describing (and condemning) Bishop Williamson’s teaching about how to make the decision whether to attend the new mass! Although Bishop Williamson (correctly) affirms the objective principle that the new mass “does harm in itself” and is bad,² he says that the decision of one’s conscience cannot be commanded by this objective principle (viz., the principle that the new mass is bad and “does harm in itself”). Instead, Bishop Williamson teaches that people should “make your own judgments”,³ using “the real and concrete conditions or circumstances in which one must act”.⁴ Plainly, Bishop Williamson is teaching the heresy of Situation Ethics!

Again, in 1956, the Holy Office explicitly condemned all types of Situation Ethics. The Holy Office warned that:

The new morality ... [has] insinuated itself even among Catholics, despite the fact that it is contrary to moral doctrines as taught and applied by the Catholic Church. Situation Ethics rests not upon principles of objective ethics rooted in being itself, but rather it claims to transcend the limitation of objectivity. Promoters of the system maintain that the ultimate and decisive norm of human activity is not some objective order of right, determined by the law of nature and certainly known in virtue of that law. Rather, they assert that the correct rules of moral action lie in some intimate light and judgment rooted in the mind of each individual person [i.e., we should decide for ourselves whether evil things are nonetheless “right” for us]. This subjective intimation enables one who is placed in a particular concrete situation to determine for himself what he is morally obliged to do right now in each case. There is no dependence on any immutable rule of action external to man; there is no measure of truth and rectitude beyond oneself; man suffices for his own moral guide.

Acta Apostlicae Sedis, 1956, pp. 144-145 (bracketed words and emphasis added).

What the Holy Office describes here (and condemns) is exactly how Bishop Williamson teaches that we should decide whether to attend the new mass! Although he correctly teaches the objective principle that the new mass is bad and does harm in itself, he scandalously tells people that the ultimate and decisive guide is not this objective principle (that the new mass is bad) but rather, their own “case-by-case” judgment of their own situation. In other words, Bishop Williamson tells people that “the ultimate and decisive norm of human activity is not some objective order of right”.⁵

Instead of following the objective principle, Bishop Williamson tells people to decide whether to attend the new mass based on their own light and judgment. That is (in Bishop Williamson’s words), he tells them to trust their own judgment ... I’ve got to use my own mind in my own circumstances.

His words exactly echo this condemned heresy of Situation Ethics! As the Holy Office warned in 1956, concerning people who promote Situation Ethics:

[T]hey assert that the correct rules of moral action [e.g., deciding whether to attend the new mass] lie in some intimate light and judgment rooted in the mind of each individual person ... [using the] particular concrete situation to determine for himself what he is morally obliged to do right now in each case ....

Let us pray for Bishop Williamson, who is afflicted with the mind rot of Situation Ethics! He has done much good in the past and could yet do more good in the future.