Inductive reasoning and deductive reasoning represent two polar approaches to critical reasoning. But what is the difference between inductive and deductive reasoning? We’re going to break down inductive vs deductive reasoning by looking at their definitions as well as some examples. By the end, you’ll know how inductive and deductive reasoning are used, and how to implement them in your own writing.
Inductive vs Deductive Reasoning Examples
What is inductive reasoning?
Inductive reasoning is a “bottom-up” process of making generalized assumptions based on specific premises. Inductions are usually made at a subconscious level, but they play an integral role in our actions and beliefs. For example, an induction could state that everybody at a party was wearing blue shirts, Laura was at the party, therefore she was wearing a blue shirt.
Bottom-to-top reasoning
Effective for world building
Predictive, not certain
How to Tell Inductive from Deductive
What is deductive reasoning?
Deductive reasoning is a “top-down” process of understanding whether or not an assumption is true, based on logic and experimentation. Deductions begin with a general assumption, then shrink in scope until a specific determination is made. For example, a general assumption may state that all dogs have eyes; this is a logical premise, but I could argue that I have eyes, therefore I must be a dog, which would prove the deduction to be illogical.
Top-to-bottom reasoning
Effective for reaching certain conclusions
Not a “foolproof” method
Deductive Reasoning or Inductive Reasoning
Inductive vs deductive reasoning
What is inductive vs deductive reasoning?
Inductive vs Deductive Reasoning Examples
Deductive reasoning is a top-to-bottom approach that stipulates that defined premises must add up to a true conclusion. It starts with a theory that can be tested through experimentation which results in a determination.
Conversely, inductive reasoning is a bottom-to-top approach which stipulates that specific observations can be used to draw general principles. It starts with a determination that can be tested through experimentation which results in a theory.
Let’s use deductive reasoning first:
If the premises state:
- All good dogs follow their owner.
- My dog is a good dog.
Then the logical conclusion would be:
- Therefore, my dog will follow me.
This deduction is logically sound. What does “sound” mean? Soundness, in a philosophical sense, is proof that an argument is both logically valid and its premises are true. If the conclusion is proven false, then the deduction will be logically unsound.
For example, if my dog doesn’t follow me, then either the premise “all good dogs follow their owner” or “my dog is a good dog” has to be unfounded. In such a case, one must adjust the premises and conclusion, or abandon the hypothesis altogether.
Inductive reasoning works the opposite way.
For example, if the observation is:
- The home team has won every game I have attended.
Then the logical induction would be:
- The home team will win the next game I attend.
This induction is known as predictive because it predicts the likeliness of a future event based on past data. Predictive inductions are just one type of inductive reasoning; there are many more.
Inductive and deductive reasoning may sound like difficult concepts to understand – but they’re actually very simple. Of course, the intricacies of the subtypes can get tricky; I find myself getting tricked up from time to time. But just remember: deductive reasoning is a top-to-bottom approach and inductive reasoning is a bottom-to-top approach.
What Does Inductive and Deductive Mean?
Inductive reasoning examples
Inductive reasoning is an exercise in generalization; AKA taking specific observations and generalizing them into greater truths.
Inductive reasoning is a probability metric.
Inductive logic dictates that specific experiences can be used to induce conclusions. So, what does this process actually look like?
Let’s break down some different types of inductive reasoning!
GENERALIZATIONS
Take a specific observation and make a generalized conclusion.
- There was a home run in the last baseball game. Therefore, there will probably be a home run in the next baseball game.
STATISTICAL
Statistical inductions take data into account to give a more accurate prediction.
- There has been a home run in seven out of the last ten baseball games. So, there’s a 70% chance there will be a home run in the next game.
BAYESIAN
Bayesian inferences add circumstantial information to statistical data.
- I’ve only ever seen baseball games at one stadium, so my data may not accurately reflect the whole league.
ANALOGICAL
Comparing two things with a shared quality and inducing that they must have another shared quality too.
- Your favorite player hit a home run. My favorite player hit a home run. Therefore, your favorite player and my favorite player are the same player.
CAUSAL INFERENCE
When you infer a causal correlation between two events.
- I only see players hit home runs during night games. I suspect I’ll see a home run tonight since I’m going to a night game.
Inductive reasoning is used all the time in everyday life. Next time you think about a “foregone conclusion,” consider how that perspective developed – what observations or experiences made you think that way? And how can you improve your inductive reasoning to better reflect the complex nature of critical thought?
How is Deductive Reasoning Different from Inductive Reasoning?
Deductive reasoning examples
Deductive reasoning dictates that assumptions can be proven true or false by matching the veracity of premises to a conclusion.
For that reason, deductive reasoning is a certainty metric.
But what does “the matching of premises to a conclusion” look like in practice?
Let’s break down some different types of deductive reasoning!
SYLLOGISM
Syllogism states that if A=B and B=C, then A=C. It takes two separate clauses and connects them together.
- Carrots are vegetables, vegetables are plants, therefore carrots are plants.
MODUS PONENS
A modus ponens is when a deduction is presented as a conditional statement, proven by subsequent clauses: the antecedent and consequent.
- Every person in my group has brown hair. Carlos is in my group (antecedent), therefore he must have brown hair (consequent).
MODUS TOLLENS
A modus tollens is the opposite of a modus ponens. Whereas the latter affirms a conditional statement, the former refutes it.
- The boiling point of water is 212 degrees Fahrenheit. The water is colder than 212 degrees Fahrenheit (negation of the consequent), therefore it will not boil (negation of the antecedent).
Inductive and deductive reasoning may be two polar strategies to critical reasoning – but they’re both incredibly useful.
Up Next
What is an Allegory?
Want to learn more about how philosophical principles are used in writing? Check out our next article on the art of allegories in which we break down examples from Snowpiercer, Fight Club, and more. By the end, you’ll know what an allegory is and how it’s used in film/literature.
