Picture the following situations in your mind's eye:
Reading these sentences, you've probably made some assumptions about the situation, those involved, and how you'd react. While you could not see them visually, it's pretty easy to paint a fairly detailed picture in your head, and get you to start making judgments, drawing conclusions.
While some claim it isn't, and still more wish it wasn't so, humans perceive the world visually. The first visual impression we take in tells us much about a person - gender, age, physical well-being, occupation, marital status, demeanor, a basic set of opinions, habits, and religious beliefs, to name a few. We gather information by looking at things. Most communication is non-verbal - through body language and appearance.
Good communication is built on a foundation of truth. In order to convey ideas with integrity and clarity, we must do our best to represent ourselves clearly and truthfully, without ambiguity. The basic assumption people have when they interact is that people are telling the truth. Subverting this assumption is dishonest. It creates confusion and frustration, and true communication breaks down, much like it would trying to converse with an angry child who speaks only Mandarin Chinese.
Imagine another scenario. You ride the bus to work, and after a while you recognize an attractive woman around your age takes the same route every day. You invite her out for coffee, and things go well. On your second date, when she shows up and takes off her jacket, you notice her arms covered in tattoos of skulls, snakes, and pentagrams. This would be rather shocking, and unexpected - you had a perception of what this woman was like, but this unexpected revelation completely shatters that impression.
Truth and honesty are virtues, and how we communicate and interact with others should be as true and honest as we can be. More often than not, our faces do the heavy lifting for our critical non-verbal communication. Like we've seen over the past few years with masks, covering up or changing faces makes it harder to communicate; make-up performs a similar function, but in a more subtle manner. Of course, there are always exceptions, but we should argue for general principles, and we can pick nits later.
Make-up is used to lie about one's appearance for the sake of vanity, or for fooling people. It obscures the truth that body language conveys and, at best, creates confusion and distrust. At worst, it's a money- and time-sink, inspires lust in men and body-image issues in women, creates unnecessary waste, and gives bad people more power and money. Make-up culture promotes the wrong ideas about what is beautiful and valuable about a person. Outside of theater or other forms of artistic dress-up, there is no moral reason for regular people to publicly wear make-up.
It's not wrong to clean up, eat healthy, and exercise regularly. But spending hours upon hours in the gym for the sake of a 6-pack and big arms is not pursuing health, it's pursuing a specific appearance for the sake of itself, which is vanity. "I like it" and "I want it" are not sufficient reasons for any important decision. Similarly, using make-up for one's own personal satisfaction isn't a good goal. There should be something deeper than "I feel prettier" or "it boosts my confidence". Why does it boost your confidence? Do you have some deep-seated dissatisfaction with your own appearance? Is changing the way your face looks that important? Maybe you should concern yourself with the root cause, instead of literally covering up the problem.
A potential argument: a small amount of makeup enhances what's already there, without fundamentally changing everything. But this misses the point; what's wrong is always wrong, no matter the degree, and a little fib or a white lie is still a lie. Everyone's definition of "just a little bit" is different. It's not technically adultery to wink at the hunky bartender or tell the barista she's cute, but that is a very uncomfortable precedent to set. This is the same argument pro-abortion advocates make - "but it's fine in cases of rape, right?" It's classic foot-in-the-door, slippery-slope stuff. The only place it leads is further down and further in.
Another reason make-up is used is to increase one's perceived beauty, or make the user look more like what society has deemed beautiful. This is usually done to attract romantic attention, but by heavily leaning on the appeal to physical attraction, the attention will have impure intentions. A good, pure relationship does not begin with lust and lies.
Heavily modifying one's appearance to fit conventional standards of beauty only further enforces those standards, and creates a further perceived need for make-up, much like an addictive drug - "I won't be pretty if I don't use it". Every one of us is beautifully and wonderfully made, and we are all very diverse in appearance, and accordingly, we all are physically attracted to different types of faces and bodies. For those concerned about being unattractive, using make-up to pretend to be like everyone else will not help find someone attracted to you - you'll instead find those attracted to fake make-up you, which looks just like everyone else. I know plenty of married people who are not conventionally attractive according to modern beauty standards, but obviously are attractive enough to their own spouse. The last thing anyone should be worried about if attempting when attempting to get a date is looking like a generic clothing advertisement model. While first impressions are important, what's more important in a long-term relationship is our inner beauty. Looks are hardly even a good filter - the most successful way to narrow down your potential pool of worthy spouses is to go to Church, or some other event where you'll have some core value in common. In fact, it's probably to one's advantage to not be conventionally pretty, so as to ward off all the attention from shallow losers. I will never again look like I looked at age 23, when I got married. If my wife and I heavily relied on physical attraction to be invested in our marriage, well, all I have to say to that is my hair's beginning to gray, I've got lines on my face, and my biceps aren't as big as they used to be. So is this it for me?! Of course this is ridiculous - but it's clearly wrong to build a relationship on a foundation of superficiality, and that's what using make-up encourages. Your face looks how it looks, and there is not much you can do about it, and even less that you should.
I've had quite a few years to look at my wife (very close up, in fact) and I know her face, and adore it. When she uses make-up (minimally, and very rarely) she looks unlike herself, and it's unsettling. Now imagine that the other way around. Say you begin a new job, and get all decked out in paint to make a good impression. One day a few weeks in, you don't wear make-up for some reason. Like the example above with the woman with terrifying tattoos, there will be some sort of reaction by those around you: you'll be told you look sick, tired, or worse, not like yourself - the make-up face has become the "you" that people perceive, not the real you. Making oneself up to always be different than what one actually is, under the surface, is misrepresentation of reality. Looking in the mirror and not seeing one's own face staring back has to be psychologically damaging - it seems obvious.
The obvious counter-argument to me claiming I'm fooled by make-up is an appeal to my own intelligence, so I'll take the bait. "You can't seriously be tricked by green eyelids, right? You can't think that's real, you're smarter than that." Most of the time, colors blend and fade and it's not obvious where "fake" begins and "real" ends. The green eyelids could be a red herring: "ok, the eyelids are green, so that's fake, but the rest looks normal, so it must be real." Most make-up is meant to be subtle, or major structural changes undetectable from anywhere but close-up. I don't think most people are going to be savvy enough to, at first glance, detect what is true and false on a person's face. The things that stick out, obviously stick out, but unless it's rather obvious stage or costume make-up, it's supposed to look normal.
St. Thomas Aquinas notes that make-up is acceptable only in one circumstance and in no others - and it's kind of a hard situation at that. He cites Gregory and Augustine in this passage, and it's worth a read, since he makes the argument better than I do.
Our bodies and our visual appearance are important communication tools, and gifts from our creator God. We should treat them well and use them well. Do we know better than God how our faces should look? Do we get to decide what truth we show others?
Make-up is a self-serving lie, motivated by impurity. Plain and simple.
What about burn victims, or people with scars? Should we erase the events of our lives that have had an impact on us? This is what the other arguments come down to: they are just being used as leverage, arguing from the specific to the general case. Typically these arguments don't actually care about the specific case being argued. It's important to come to state broad opinions first, then we can work out all the details. We must return to the premise of the argument: using make-up alters one's appearance significantly so as to effect the truth of how one is perceived (it's a lie, written all over one's face). Lying is wrong, therefore it is wrong to use make-up.
At least in Western countries, make-up is culturally "normal". Most people don't think anything about women wearing make-up unless they're weirdos like me. I'm not trying to shame any specific women for abiding by the norms of their culture. After all, if the modern standards for beauty tell you that you should do this thing, and nobody says "no", why would you not? I just urge you to think about it. There are many people in the world who know you're beautiful just the way you are, without trying to look like some unattainable standard that isn't you.
Did you disagree? Email me! Let's talk about it! That's my position. I'd love to hear yours. If you write something, and you're okay with me posting it publicly, I will put it on this page.