Marie Kondo's "The Life-Changing Magic of Tidying Up," the top-ranked book on The New York Times list of self-help books, promises that, once your house is orderly, you can "pour your time and passion into what brings you the most joy, your mission in life." —the Times.

Illustrations by Emily Flake

When tidying up in a house that contains a baby, the first thing to consider is the question of ownership. To whom do the onesies, blankets, and toys belong—you or the baby? A good rule of thumb is: if it's something like a hairbrush or nail clipper that you use on the baby, it belongs to you; if it's something that the baby uses, like the blankie or the iPad, it belongs to the baby.

Obviously, babies cannot speak. This may prove problematic when you are trying to determine whether or not the baby's belongings are sparking joy in the baby. If you are particularly attuned to your child, you might be able to tell when that rush of joy floods his or her little body. If, however, you are unable to do so, you must shoulder the responsibility of determining the joy-inducing capacity of any given object until your child is sufficiently verbal.

The KonMari method dictates the separation of adult belongings into categories. With baby items, the lines become fuzzier: is a binky with a woobie attached a toy, or bedding? Is a Moby wrap clothing, or a noose? Best, then, to simplify into only two groups: onesies, and anything that is not a onesie.

When considering a onesie, it is important to remember that there is no such thing as a onesie that sparks joy. This may confuse you, if you are still able to dimly recall a time when onesies were capable of sparking joy. You may remember cooing over their smallness, chuckling at the clever phrases printed on them, and thinking, “It is important that the world perceive my baby to be a Ramones fan.” But this was all before you gave birth. Now you know the truth—that babies grow out of onesies on a weekly basis, and that no matter how darling the graphic, everything stops being cute when it is covered in fecal matter. So never forget: onesies are disposable.

For the non-onesie category, the process is as follows. Gather all items into a pile. Begin to sort through them one by one. Does that black-and-white book about animals spark joy? Or does it inspire irritation, because really, how on earth could somebody be the "author" of something that is just a list of eleven nouns? Is the plastic needlepoint alphabet set in the plastic needlepoint box that your mother picked up at her church bazaar sparking joy, or a cold rage that has nothing to do with the item itself and everything to do with your mother? This bottle of Thunderbird sparks joy, but does it belong among your child's things?

The important thing to remember is that the joy these items spark is ephemeral at best, contained in the moment when they were first received. Thank the items for it, and then set them on fire.

New things, of course, will wend their way into your home, brought by well-meaning friends and relatives. And it will be difficult for them to understand why their gifts are being received with gut-wrenching sobs. When they ask what's wrong, your choices are these: You can pause, take a few deep breaths, and explain to your mother-in-law that while you truly appreciate the time she took to crochet the abomination she’s calling a baby blanket, it is very important that your home be as neat as possible, and a tangle of scratchy, pink acrylic yarn does not have a place in it. Alternately, you can keep your feelings hidden until they leave, and then pick that god-awful blanket apart stitch by stitch. It’s remarkably meditative.

Finally, we come to the baby. When determining the level of joy sparked by your baby, remove your baby from its crib and run your hands over it. Does the baby spark joy? Are you, indeed, capable of joy anymore? If the baby sparks nothing but a black, yawning chasm of fear and doubt, thank the baby for its service, fold it, and store it in a cool, dry place. (A tip for storing your baby: Fold along the center line, then fold the edge in to create a rectangle, roll up—face-out—and place in closet.)