Sheeplock and Dachson had just returned from a weeklong vacation which saw them speaking to London Yard about proper investigative techniques, then scaling the fjords of Norway and finishing with a relaxing weekend of Goat Yoga as the goat leading it was an old friend of Sheeplock. The yoga even featured the new trendy Brayfast as the morning meal choice. They were rested and ready and that’s a good thing, as they weren’t back but 10 minutes when the phone rang requesting their skills immediately.
Minutes later they were on the scene at the local college fraternity where there was an uproar over whether their food was safe to eat. Someone, it seems, had given them a tray of delicious chocolate brownies at a party that day. During the party, several students started acting strangely, contemplating the nature of leaves, wondering why there aren’t more colors and just generally acting chill. Were the remaining brownies safe to eat? Sheeplock questioned the guests acting normally, “Did the first student acting strangely after eating the brownies?” and the answer was yes. “Did the second student act weird after eating the brownies?” and the answer was yes. For the rest of the students acting odd, they had always eaten the brownies. Sheeplock stood tall and pronounced I have used my powers of deductive logic (to which Dachson scowled) er, excuse me, inductive logic to determine that the brownies are indeed making people who consume them act strangely. Only consume them if you too would like to act so oddly.
Inductive logic is when we move from specific observations to a general conclusion. As an example, let’s say there is a cookie jar in front of me which is opaque so you cannot see into it. I open it, take out a chocolate chip cookie and eat it. I open it again, take out another chocolate chip cookie and eat it. I open it a third time, take out yet another chocolate chip cookie and eat it (I like this example!). If you were to say the cookie jar only contains chocolate chip cookies – that is inductive reasoning. You had several observations of only chocolate chip cookies coming out, so you logically reasoned there are only that kind of cookie inside. It’s important to note that this conclusion may or may not be actually true. The next step is to set up a test to confirm your conclusion. Perhaps you will lock me in the room along with a camera for monitoring and hot coffee to dunk the cookies in. Then you watch me eat the rest of the cookies and see what kind they are (what an awesome experiment!). Inductive reasoning can have true premises but a false conclusion: All sheep have hooves, a horse has hooves, therefore a horse is a sheep. That is obviously false.
We use inductive reasoning routinely in our lives. If you drive to work and encounter a 15-minute delay due to traffic, see the same thing the next day, and the next, you will probably conclude this road always has traffic at this time. Inductive reasoning doesn’t need to know why there is a 15-minute delay, just that there is one. You could then use deductive and abductive reasoning to determine the cause of the delay. You could see that a local factory has a nightshift that finishes at the same time and abductively reason it is the most likely cause of the traffic. Or you might deductively reason that this road is the only onramp to the highway and most people need to use the highway to get to work therefore this road is more crowded.
It’s thought that our ancestors used inductive reasoning to determine what was safe to eat. Some people may still need to use it. For instance, you stop at your local gas station convenience store and discover they now sell raw sushi, so you eat some and later that day get violently ill. Thinking it was a fluke you try again next week and get horribly ill again. Are you willing to try a third time? If not, you are probably using inductive logic to conclude their sushi isn’t the best. If an early human watched their friends eat some wild mushrooms and then die, he or she might have used inductive logic to conclude he should not eat that mushroom.
Now you have the 3 forms of reasoning at your disposal: inductive, deductive and abductive. You are now fully trained and ready to conquer the world, or at least analyze the arguments you see around you. If you see someone using inductive logic you know the conclusion doesn’t have to be true even if the premises are. With deduction, if the premises are true then the conclusion must also be true, so check those premises. Finally, abduction can only tell what is the most likely conclusion and also doesn’t have to be true. Now, if you could please check that lab camera, you’ll notice I’m almost out of cookies.