The Psalms speak constantly of the evil of guile. Indeed, the Psalms warn us much more about the evil of guile than of lust. Come to think of it, so does the Pope. One of my prayers for the New Year is that I will make headway against this evil in my own life.
Ramah, the Hebrew root of the word mirmah, refers principally to shooting, or throwing stones. Mirmah, then, means deceiving, fraud, treachery, falseness, guile. “Lo, the wicked bend their bow, they make ready their arrow upon the string, that they may in the darkness shoot at the upright in heart” (Ps. 11:2).
Let us define guile this way: it is (a) speech, that (b) is not true, and (c) aims to hurt. And let us discover how often we use it: “Examine me, O LORD, and prove me; test my kidneys and my heart. For thy lovingkindness is before mine eyes: and I have walked [or: I wish I had walked] in thy truth. I have not sat with vain persons, neither will I go in with concealers” (Ps 26:2-4).
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The purpose of speech is to bring people together by reference to something else: the topic of conversation. Guile undermines this, both by turning speech into a hurtful weapon instead of a tool of love, and by speaking about something that is not true, and so creating a bond over something that isn’t really there.
We can engage in this kind of speech in various ways. First, with different 
people. The one we hurt can be the one we are speaking to, when we use speech to demean the person in front of us. We can also demean someone who is absent, as when we gossip and say bad things about people who aren’t there.
And guile can be part of our interior monologue – do other people talk to themselves as much as I do? I find myself imaginging conversations: I imagine telling other people how bad someone is, or how I would like to hurt that person with my own words to his face.
Oh, how much guile there is in my soul! How many of my conversations, and of my interior conversations!
Notice, too, that guile can affect our speech in non-verbal ways. The way we say, “yeah, right” can be aimed to hurt. Our tone of voice can so easily turn innocent words into weapons.
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It is not always wrong to wound with words. If speech is meant to bring people together in the truth, then in fact there is a place for criticism. The problem is that so often our criticism is not true.
Here’s where I experience this most directly: when I say the words “you can’t just . . . ” to the kids. “You can’t just eat candy all day long.” Okay, well, that’s true enough. But were they asking to eat candy all day long? Were they asking to “just” eat candy? Was what they were asking for even candy?
Of course I must often tell my kids that they can’t eat what they’d like to eat. But when the words exaggerate, they create distance. I am being unfair, criticizing something they haven’t actually done. That unfairness, in fact, prevents my children from hearing the legitimate point I want to make – because the point I am actually making is not legitimate.
Exaggeration is untruth. It undermines what words are for. If I exaggerate about someone not present, I do harm in so many ways: I injure the person we are talking about, both by attaching a falsehood to their reputation, and by using my words to create greater distance between me and them, rather than love. And I also hurt the relationship in front of me, because I am building that relationship on sand, on untruth, that will not last; and on hatred, which can only come back to hurt every relationship.
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How can we fight this? “Out of the abundance of the heart the mouth speaks” (Matthew 12:34). The friends of St. Dominic said he spoke “only to God and about God.” If our interior conversation were directed toward God, I think we would be less inclined to speak untruth, because we know he knows it is untrue.
And as James says, “we put bits in the horses’ mouths, that they may obey us” (James 3:3). Perhaps we can do a lot to steer our whole behavior by realizing that the words we speak are central to who we are. We might make a lot of progress just by taking the advice of so much of the Bible and the Tradition, and focus on our speech: make sure it is in love, and make sure it is true.
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How does guile express itself in your life? Have you found any good strategies to fight it?