Sherlock Holmes got his logic wrong.

When he bragged about his "deductive" powers, he was actually using a far more useful tool: inductive reasoning.

Our view of reality—at least the logical part of it—comes from three sources, according to Aristotle:

• Facts, or what we infer from them;

• Beliefs; and

• Definitions.

Let’s start with facts and beliefs. They anchor the two kinds of Aristotelian logic, induction and deduction. We tend to get confused about these two, in large part because of Sherlock Holmes. That silly detective bragged about his deductive powers when most of his sleuthing had to do with induction.

Why does it matter whether your logic is inductive or deductive? Because the tools we will use to bend our souls toward our goals depend on using the right one for the right occasion. Induction gathers facts and reaches a conclusion or tells a story. Then there’s deduction, which offers a means of sweet instant persuasion.

Still, if you’re anything like me, formal logic has always confused you a little bit. Let’s turn that confusion into healthy self-manipulation.

Induction: Detect the Cause

Inductive logic deals with the facts and how you interpret them. Imagine taking a hike with a friend in the New Mexican desert near Area 51. The two of you spot a basketball-sized object partially embedded in the sandy gravel.

“What is it?” your friend asks.

You approach with trepidation. Most of this region is controlled by the Air Force, whose straying objects tend to explode. But as you get closer, this thing begins to seem weirdly transparent. What bomb would be see-through?

It’s time for Aristotle. His version of the scientific method—a system of observation that still gets taught in science and philosophy classes today—breaks down any unidentified object into four “causes.”

First, the material cause: “What’s that thing made of?” you ask. Good job. The material cause is just what it sounds like: an object’s makeup. Is this mysterious thing made from some kind of plastic? Or…

“Whoa, it moved!” You both stare: the thing is…undulating! This implies that the material is organic.

“Who do you think made it?” your friend asks. The two of you stare at each other, wondering who will say it first. “Aliens?” You’re trying to work out the efficient cause, which has to do with the producer of an object.

“Maybe it’s some kind of half-living computer brain,” says your friend, who reads science fiction. He is talking about the formal cause—the form a thing takes. In this case, the form might be that of a brain.

Now your friend moves on to the final cause. Feeling more confident about his theory, he says: “I bet it was the brain of an alien spaceship, controlling all its navigation and functions and everything.”

While your friend might be entirely wrong—the object could just be some toy that blew in the wind—this logical process is the single best way to examine the strange and mysterious, from interstellar objects to your own unexplored soul.

Consider the Kardashian family, that out-of-this-world collection of influencers and unnatural celebrities. What is a Kardashian’s material cause; what is she made of? Sugar and spice? Flesh and Botox? A Kardashian’s efficient cause seems even trickier to assess. Who or what “makes” a Kardashian? God? Attractive genes? Or maybe social media? If a Kardashian were stranded on a desert island, would she still exist? Her formal cause, on the other hand, is pretty much a no-brainer. A Kardashian is a celebrity. Just as the form of the object you’re sitting in is “chair,” a single Kardashian forms “celebrity.” Now, her final cause remains a mystery. What is a Kardashian for? To be honest, I’m stumped here.

Let’s leave the Kardashians (you’re welcome) and examine your own final cause. What are you for? We’re not necessarily talking about your “calling” or “vocation,” the purpose for which you were put on the planet. That might be an aspect of your final cause; but when it comes to the final cause of a person, Aristotle would say that it has to do with the ultimate expression of personhood. He’s talking about your best life. At the very center of that best life lies your soul.

Meanwhile, you can use inductive reasoning to see reality more clearly. Imagine yourself to be Taylor Swift, you lucky thing. You are planning your next big concert tour. (I mean, seriously. This would make a decent role-playing game.) You decide that the next big theme will revolve around a color. In fact, why not first record an album around a particular hue? Being the marketing genius you are, you research the trends. What color does your core audience—twelve- to twenty-five-year-old females—tend to favor most? You, Taylor, follow Aristotle’s four inductive steps.

First you ask: Is it real? Do girls and young women actually prefer a particular color? You get your people on it, contacting the Pantone color folks and maybe holding some focus groups.

Next, what’s the origin? Who or what determines whether a seventh-grade fashionista’s new backpack is Barbie pink or pansy purple? Who are the color influencers on TikTok? Or are the trends mostly manufactured by the backpack designers? Knowing this can help Taylor anticipate next year’s hot color.

Third, why? What’s the reason for pink versus purple? Does it have to do with the national mood? The rebirth of Barbie? Just what force drives color preferences? What influences the influencers?

Finally, is this a trend? Is pink on the rise, or has it peaked and gone past its sell-by date?

This color-trend-finding follows Aristotle’s inductive “causes”—material (is it real?), efficient (what’s the origin?), formal (what’s the reason, or what can we honestly call this thing?), and final (does this thing have a life of its own?).

Whether or not Taylor Swift ranks among your top passions, the tool of induction can improve your mood. For instance, our digital news feeds constantly bring us horrors from elsewhere: crime, wars, criminal leaders, lions and tigers and bears in trouble: oh my! Now apply inductive reasoning to each piece of news, and you may find yourself responding differently.

Your smartphone reports that a young child has been kidnapped somewhere in the Midwest. First you ask: Is the news real, or is it just rumor or downright fake? You can investigate further, or you can dismiss the item altogether. Your choice.

Next, what’s the origin? Did the news come from a source you trust, one that checks its facts and admits its errors?

Third, why did the kid get allegedly napped? Was it a divorcing parent, or a stranger?

Finally, and most importantly, what’s the trend? Are kidnappings increasing? Is the number growing nationwide, or just in that one part of the country?

Assuming you care to do the research and cogitation, you might conclude that this terrible event is a single data point and not evidence of a wave of kidnappings. In fact, you may learn that the trend has been going down for decades. You discover that in most cases we see a very sad story about feuding parents, with the unfortunate child in the middle. Tragic. But not a sign of the apocalypse.

In any major life choice we make, we accumulate facts and reach a conclusion. Before we buy a house, it helps to gather facts about housing trends and mortgage rates and crime and schools, and then draw a mental picture of our place in that reality. Aristotelian induction can make your choice more rational.

Exercise: Think back on a mistake you especially regret making. What exactly did you do? Next, what caused it—a lack of sleep, a temporary error in judgement, or a sudden “appetite” or mood swing? Why were you sleep deprived or moody? Finally, what’s the trend? Was this error part of a pattern or a one-off? If the lapse is rare and not the sort of thing you usually do, then congratulations! You have proved your virtuous rule by that exception. If you see a trend, then this may be a sign of your final cause—your soul. Maybe you have a deeper need to explore.