Today a friend of mine, who like me cares deeply about justice and fairness whether in the personal sphere or in the international one, sent me a very thoughtful and excellent paper defending the validity of the tu quoque defense in cases of international justice . As I agree fully with the argument presented in the article by the author, I thought it worthwhile to deal more generally with the partial validity of the tu quoque argument from scripture and my own personal practice.
At its heart, the tu quoque is a defense based on fairness and justice. Tu quoque means “you also” and is an argument that, when it seeks to defend against punishment for crimes that ‘the other side’ is guilty of, is valid from the grounds of both scripture and history (specifically the Nuremberg Trials). I do not concede the validity of the tu quoque argument that seeks to deny the admission of wrong for violating a moral standard, but fully endorse its use in arguing against strict and merciless punishment of violations in light of obvious questions of fairness. In short, the use of the tu quoque argument as an admission of guilt and also a pointing out that the prosecutor of those whom he represents are also guilty of the same crimes points to the preservation of mercy and justice within a moral and legal order, and that I wholeheartedly endorse.
By and large I feel (based on my experiences with others) that my position on mercy and justice is greatly misunderstood. I am a very severe and strict person with very high standards of personal behavior that I apply very consistently to others. I am also extremely aware of my own fallibility and the fact that neither I nor any human being on this earth has entirely clean hands. I reject the formulation of the tu quoque argument that says that my lack of moral perfection makes me unfit to condemn sins in others that I myself share. I accept, however, that formulation that says that I am disbarred from enforcing cosmic justice on evildoers as a result of my own moral uncleanness. Rather, because I seek justice for myself, I also give judgment to other sinners, desiring them to accept and admit their wrong based on God’s universal moral standard without desiring to enforce His punishment on fellow sinners, recognizing that as His right alone, because He is blameless and without sin, and also desires to be merciful to all who repent.
It bothers me that I am viewed as some sort of pitiless Calvinist avenger, because that’s not the way I am at all. I recognize that I am a fellow sinner and am not fit to condemn others. Nonetheless, I also recognize that God’s laws are universally applicable–both to me and to those who have wronged me in this life. The greater one is aware of their own moral failings, the more one will desire mercy for all, recognizing that without the mercy of God we will all be condemned. It is only those who are willfully ignorant of their own failings who are unmerciful and harsh toward the failings of others. However, unlike others, my recognition of my own moral failings does not lead me to assume that the law is invalid or unjust simply because I cannot meet its pitiless and exacting standard. Rather, like Paul in Romans 7, I accept that the law is holy and good, and also express my praise that Jesus Christ has delivered me (and other believers) from the sinful nature and condemnation to death for our sins.
This is also, thankfully, the way that this fairness argument of the tu quoque has been enforced in both scripture and practice. The example par excellence of the application of tu quoque comes from John 8, where the woman caught in the act of adultery was convicted of adultery, but was not punished with death because her accusers were also found to be guilty of the same law, and therefore did not have clean hands to throw the first stone . In short, contrary to the arguments of antinomians (and the concerns of those whose love for the law leads them to reject this passage), the case of the woman caught in adultery is precisely the sort of limited claim for tu quoque that I wholeheartedly admit and that I regularly practice–an admission of a violation of a valid moral or legal standard along with an equally valid argument that the violation of others of this standard makes them unfit to punish me for that sin.
This is the sort of partial acceptance of the tu quoque argument that is seen in history as well. In the well-researched and argued essay below  two Nazi German war admirals avoided punishment (but not conviction) for violation of the London protocol dealing with neutral merchant ships because the conduct of unrestricted submarine warfare had engaged in by the Americans, the British, and the Russians as well in different theaters of war. Since all parties had engaged in the same “immoral” and “illegal” acts, the Germans were convicted of their violations but not punished, and the American judge himself openly admitted that his concern for fairness and justice led him to argue strenuously for precisely that result. He was a just judge, and his fair verdict allowed moral norms to be preserved while providing mercy for those who had plenty of company in their sins. This was how Jesus behaved in the temple with the woman caught in adultery, and is my own model for dealing with such frequent problems in my own life and in the behavior of those around me.
Let us note, therefore, that this partial validity of the tu quoque argument, in avoiding the (impossible) urge for universal conviction and also the immoral and unjust desire to be pitiless and merciless on fellow sinners while vainly attempting to argue our own standing to be impartial judges in own own disputes is following the biblical standard of justice, allowing for mercy for the condemned in the recognition that we require (and receive) mercy from God for our own sins. Those who have received pardon must be willing to grant pardon to others if we desire to be just and fair judges.
Therefore, the tu quoque argument, far from being a logical fallacy, is itself valid in its formulation as an argument against punishment, though not in its other forms. Such an argument is the only way that we can preserve a respect for moral norms, and an admission that any conduct against those standards, whether our own or anyone else’s, is to be convicted, with a recognition of our need (and the worthiness of others) for mercy based on our own universally fallen and sinful state. In so doing we separate our hatred of sin wherever it may be found with our love and mercy for sinners, and our desire to be shown mercy as repentant sinners ourselves. In so doing we maintain the dignity of the law as an absolute standard while also practicing mercy on fellow sinners when we inevitably but repentantly fall short of that harsh standard. Far from being a logical fallacy, this formulation of the tu quoque is the only common ground that exists between a fervent desire for justice and equity along with a loving and merciful attitude towards fellow sinners who join us in seeking mercy and pardon for our sins, which are many.