Philosophical Ethics: A Possible Kantian Formula For Determining The Permissibility Of Self-Defense

Philosophical Ethics: A Possible Kantian Formula For Determining The Permissibility Of Self-Defense October 14, 2009

In a series of posts this semester, I am going to blog all (or almost all) the lecture topics for the two Philosophical Ethics classes I am teaching this semester. Each of these posts will primarily explicate the reading or a theme that dominated class discussion in a way that should be accessible to novices (such as my students are). I will also offer some degree of analysis of the ideas considered and then pose suggested discussion questions. These posts will usually feature more speculation than argumentation from me as I try to stimulate your thinking rather than stake out my own positions. Some of my students will be responding to these short discussion primers in a private forum through the university. I’ve told the students they are free to discuss the blog post versions of these discussion primers as well, so they might show up here. The text we are using and from which all citations will be taken is Ethical Theory: classical and contemporary readings, edited by Louis Pojman. Wadsworth: California, 2007). This post explores the Kantian possibilities for both physical self-defense in the form of counter-violence and mental self-defense in the form of counter-lies to liars.

Immanuel Kant argues that our actions, in order to be moral must be done from a “maxim” that we could universalize.  What this means is that the reason that motivates our action “One should x in situations y” should be one that you could will that all agents x in all situations y would do the same thing.  The strongest reason that you could have for being unable to will all agents perform the action propose given by a particular maxim would be that if everyone acted on that maxim it would defeat the very action which the maxim suggests you perform.  For example, you cannot will that every one always lie because in that case no one would believe anything anyone else said and lies themselves would not even be possible, making such a law inherently counterproductive to itself.

Another test for the morality of an action is to see whether it violates or upholds the principle that we should always treat humanity, whether in ourselves or in others, as an end-in-itself and never merely as a means.  Kant thinks that because we are autonomous agents, ones who act for reasons we give ourselves rather than merely according to the dictates of outside forces, it is simply irrational to act in such a way that treats autonomous agents as though they were mere things subject to others’ laws.  So when I treat you as a mere means to my ends, I treat you immorally because I try to turn you into a mere means to fulfilling my will, rather than as the free, reasoning, and self-ruling being which you are.

Lies are ruled out on this test for actions as well.  This time the prohibition against lying comes from consideration of the irrationality of treating beings who are ends in themselves as mere means to one’s own ends.  A lie is wrong because it is an act of coercion that undermines another rational being’s ability to determine his or her course of action freely by corrupting the information he or she has to work with in making decisions.  Using this line of reasoning Kant rules out all lies as a priori immoral.  He famously refuses to concede any exceptions to this rule against lying, even in the case in which lying would be necessary to protect an innocent person from a murderer at your door who is inquiring whether his intended victim is in your house.  You must respect even the autonomy of those with murderous intentions and not lie to them.

Christine Korsgaard has argued that there are arguments that Kant makes in other contexts which would seem to lay the groundwork for a Kantian defense of lying to murderers after all.  Kant allows for resistance to unjust physical coercion with defensive physical force on the grounds that being an autonomous, self-ruling agent carries with it a duty to avoid servility and coercion since to be servile to others or let oneself be coerced by others is to let yourself be treated as less than the autonomous being which you are and, so, is immoral.  Korsgaard notes that we cannot universalize a world in which the wicked were always able to exploit the goodness of the good because the good were too moral and respectful of others’ autonomy to defend themselves.  Korsgaard extends this line of reasoning to claim that Kant similarly should allow us to resist the unjust mental coercion which liars attempt to impose on us through their lies.  And the way to counter-coerce a liar is with the mental force of lies.  Just as when you hit me, I have the right to hit you back out of respect for my autonomy and even though I would have no right to hit you and so disrespect you had you not first hit me, Korsgaard thinks that when you lie to me, you try to coerce and abuse me and I have the right to hit back with a lie of my own.

But can we universalize the principle that we may lie to liars?  Would it lead to a practical contradiction?  If everyone were to act on the maxim that one should lie to liars, would that make lying to liars as ineffective as making lying promises on loan applications would make such promises futile since no one would believe them?  Would a universal law that we should all lie to liars be self-defeating to the attempts to lie to liars since liars would know this law and not trust those to whom they lie and so not be fooled by our lies?  Korsgaard argues that this is not a problem and that there is no practical contradiction.  We can universalize the rule that we should lie to liars and still the liars would be fooled, even though they knew about this law permitting lying to liars.  The reason for this is that liars only lie when they believe they can fool someone.  If they cannot fool you and they know it, they give up the pretense.  Therefore anyone attempting to lie to you does not suspect that you know that they are lying.  Therefore they cannot anticipate that you realize it is an opportunity to lie to them.  They assume that you are operating under the normal moral law against lying.  So in this circumstance when you know that they are lying and they think that you think they’re telling the truth, you can fool them with your lie.   So even though they would know the universal law that permits lying to liars, they would not realize that you know you are in a case where it applies, a case where you are indeed being lied to and so they would fall for your lie.

It is not only liars who lie for unscrupulous ends (like to murder) who may be so resisted, but even “philanthropic” liars who undermine our autonomy by lying to us for ultimately good ends.  Korsgaard gives the hypothetical example of a philanthropist looking for the most needful recipients of his aid who in order to avoid being exploited, disguises his search for poor people to help with what he claims is some other form of general census.  He lies about what he is really up to in collecting information, but his purposes are the opposite of evil.  Korsgaard says even he should be confronted about his trickery.  However, in this case she argues that since it is possible to rebuke the philanthropist without lying to him, we do not need to take recourse to lies, and so we shouldn’t, as we would in the case of the murderer who is lying to us.

I suggest we can further formalize Kant and Korsgaard’s intuitions about self-defense and counter-coercion and make a general rule that we can always counter-coerce but only with equal force.  This means, for example, we can universalize that when physically attacked we can fight back to whatever extent is necessary to restrain and subdue our attacker.  Once restrained or subdued, however, we can no longer commit acts of violence since in that case we cross the line from counter-coercion to initiation of new violence.  This is why, for example, we may kill enemy combatants on a battlefield but not torture or otherwise inflict violence upon them once we have captured and imprisoned them.  Once they are disarmed, we are not in a situation of justifiably counter violence but we are it perpetrators when we introduce it.  Similarly, we should calibrate our self-protective lies to be proportional to our needs to protect our own autonomy but not exploit liars’ lies to us as openings to abuse their trust any further than necessary.

Your Thoughts?

If you enjoy reading my philosophical blog posts, consider taking one of my online philosophy classes! I earned my PhD and taught 93 university classes before I went into business for myself. My online classes involve live, interactive class discussions with me and your fellow students held over videoconference (using Google Hangout, which downloads in just seconds). Classes involve personalized attention to your own ideas and questions. Course content winds up tailored to your interests as lively and rigorous class discussions determine where exactly we go. Classes are flexible enough to meet the needs of both beginners and students with existing philosophical background

My classes require no outside reading or homework or grades–only a once weekly 2.5 hour commitment that fits the schedules of busy people. My classes are university quality but I can offer no university credit whatsoever. New classes start up every month and you can join existing groups of students if you want. Click on the classes that interest you below and find the course descriptions, up-to-date schedules, and self-registration. 1-on-1 classes can be arranged by appointment if you write me at




Browse Our Archives