What does deductive reasoning look like?

In both our work and personal lives, we make thousands of decisions each day.

Many decisions come naturally, like what to eat for lunch or what time to clock in for work.

Others, though, need a more thorough system to reach a decision that makes sense, such as when determining whether to use a drywall nail or a finishing nail.

There are a few ways we can achieve this, and one is deductive reasoning.

Deductive reasoning is a method of logical thinking that starts with high-level assumptions and follows a course of relevant statements to reach a decision or conclusion.

We’re going to show you exactly how to use deductive reasoning in the workplace, explain some of the main benefits of using this form of logic, and introduce you to two other kinds of reasoning that are similar.

What is deductive reasoning?

Deductive reasoning is a method of reasoning that allows you to reach a conclusion that is:

• Logical - makes sense

• True - fact-based

• Valid - well-grounded

It’s important to reach these kinds of conclusions, as it means you’re more likely to be correct in your decision making.

Also known as deduction, deductive reasoning starts with a general statement (that is known to be true), and compares that with a second true statement.

From those two statements, a logically true conclusion is drawn.

Let’s look at an example:

• First premise: A potential employer is looking for someone with a fork hoist license.

• Second premise: I have a fork hoist license.

• Logical conclusion: I would be a valid candidate for this position.

This type of reasoning, sometimes referred to as top-down logic, has a long history, dating as far back as Aristotle.

Deductive arguments may follow several premises (factual statements) as opposed to the simple example above, though as with most things, less is more.

The general guide for deductive reasoning is that if all premises are true, then the final conclusion must also be true.

We can use deductive reasoning in a few different ways.

Let’s take a look.

The 3 types of deductive reasoning

There are three main types of deductive reasoning:

1. Syllogism

A syllogism is a form of deductive problem-solving that typically appears in a three-line form. It is the style we used in our fork hoist example.

In a syllogism, a common term appears in the first two lines (premises) but not in the conclusion.

If you're in sales, for example, you can use syllogisms to draw conclusions about your customers, for example:

1. If a customer is interested in buying Product A, they have Problem X.

2. If a person has Problem X, Product B is also a good solution.

3. Therefore, if a customer is interested in Product A, they might also be interested in Product B.

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2. Modus ponens

This reasoning process involves an original premise which is a conditional statement (If X, then Y), and a second premise which tells us that the first part of the original premise (X) applies.

It’s helpful in the workplace for understanding customer needs.

Imagine you work as a waiter:

1. If a person likes cheeseburgers, they like other cheesy meals, like mac and cheese.

2. John orders a cheeseburger, but you’re out of cheeseburgers.

3. John might also like mac and cheese, so you can suggest that as an alternative order.

3. Modus tollens

This method takes the general principles of the modus ponens method and flips them.

The flow of thinking is the same, except the second premise tells us that the first part of the original premise (X) doesn’t apply.

In the workplace, it helps us to determine what products might not be suitable for our customers.

Taking the above example:

1. If a person likes sour cream, they like cheese.

2. Brian asked for no sour cream on his nachos.

3. Brian might also not want cheese, so it’s logical to ask him if he wants his nachos without cheese also.

Knowing when to apply each of the three kinds of deductive reasoning will help you to reach logical conclusions quickly, such as determining which of your colleagues are peanut butter fans.

Deduction is not the only method we can apply, though.

What is the difference between inductive and deductive reasoning?

Where deductive reasoning takes a top-down approach to reach a specific conclusion (known as a deductive inference), inductive reasoning takes a bottom-up approach.

Basically, you start with some form of information and draw a general conclusion from that data.

Let’s take a look at an example to illustrate inductive reasoning:

• The first customer that called today has a problem with her internet connection.

• The second customer also had an issue with his connection.

• The third customer is facing the same problem.

• Therefore, all the customers that call today will have a problem with their internet connection.

The difference is that deductive logic starts with the general and moves toward a narrower conclusion, whereas inductive logic starts with information drawn from specific scenarios and draws a conclusion from that information.

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Be aware when applying this logic, as Inductive reasoning does leave room for conclusions to be false.

Deductive reasoning does too, but only if any of the premises are untrue.

Inductive reasoning can be a great way to come to a decision that is most likely true, but it’s important to ask yourself whether there are any alternative solutions.

With inductive reasoning, it is possible to make an observation that is incorrect, even if the premises are true.

Let’s look at our internet example.

Suppose the first three customers that call do have internet issues, and we make the assumption that everyone who calls today will have the same issue.

That’s pretty unlikely, right? And so if we draw that conclusion, we risk being unprepared to solve other kinds of issues.

In this case, our inductive argument has led to an incorrect conclusion.

You can prevent yourself from falling into this trap by double-checking your conclusions using other forms of reasoning, such as deductive or abductive reasoning.

Let’s take a look at that third form of logic: abductive reasoning.

What is the difference between inductive and abductive reasoning?

Where inductive reasoning works backward from a few specific pieces of information, abductive reasoning looks at a few observations (that don’t necessarily give the full picture), and draws them together to give the most likely explanation.

This kind of reasoning is important in the workplace because you don’t always have a complete set of information to work with, so it helps you to reach a well-founded conclusion based on the information you do have.

It’s sort of like making an educated guess based on the information you have at hand.

Be careful, though, because drawing conclusions from incomplete information does leave room for error.

Let’s look at an example:

You’ve applied for twenty jobs now, and haven’t gotten a single interview. You check our resume and notice a spelling mistake in the first line. The conclusion of your draw is that you’ve been unsuccessful because employers weren’t impressed with the spelling mistake.

This is certainly an explanation that could be correct, but it’s not the only one that could be true.

For example, it might be that you’ve applied for jobs that you aren’t qualified for, for example.

You can see here how abductive reasoning can lead you astray, as in the example you’re likely to fix the spelling mistake and keep applying for the same roles, rather than realizing that you’re not a valid candidate for that kind of position, and focusing your search elsewhere.

What is an example of deductive reasoning?

Though the framework for deductive reasoning can seem quite specific and perhaps even a little difficult, it’s surprisingly straightforward in practice.

| Let’s dig into a few learning examples. | | ------------- | | **First premise: **This job requires someone with management experience
**Second premise: **I don’t have any management experience.
Conclusion: I shouldn’t apply for this role. | | **First premise: **Employers are looking for people who interview with confidence.
Second premise: I’m a confident person.
Conclusion: I should do well in an interview. | | **First premise: **Carrots are orange.
**Second premise: **Oranges are oranges.
**Conclusion: **Therefore, carrots are oranges. |

As you can see from the above example, deductive reasoning still leaves room to be incorrect, so deduce with care!

Thus, it's a good idea to use more than one form of deductive reasoning to double check your conclusions.

The benefits of using deductive reasoning

As you’ve seen, deductive reasoning tends to be a more appropriate method for reaching a justified conclusion than the other types of thinking, such as inductive and abductive reasoning.

But, how does deductive reasoning help in real life?

Benefit 1: Make smarter decisions at work

Efficient and effective decision-making in the workplace is a skill that is valued highly by many employers.

If you’re able to use deductive reasoning to reach logical conclusions and make decisions without assistance, your manager is likely to be impressed by your initiative and autonomy, as is your prospective manager when applying for new roles.

Benefit 2: Decide which career paths make the most sense for you

It’s no secret that people are changing career paths more frequently than ever, with around 30% of the labor force switching jobs every 12 months.

Though this can be great for developing a broad collection of experience, it’s often the case that an employee seeks to change careers because they just aren’t sure of their path.

Deductive reasoning can help determine whether a career or job change is appropriate or whether you’re better off staying put.

Benefit 3: Understand where your decision-making went wrong

You’re not always going to have the opportunity to take some time out and apply a specific reasoning methodology.

Often, you’ll have to think on your feet and make decisions quickly.

Sometimes you’re going to make the wrong choice. That’s okay.

With the power of deductive reasoning on your side, you’ll be able to look back at your decision-making process and figure out how you can handle the issue wisely in the future.

How and when do you use deductive reasoning?

Here are three times deductive reasoning is useful:

• **To determine whether a job is a good fit for you. **When applying for new jobs you can easily apply the deductive reasoning concept to determine whether you’re a good fit. Start by listing out the candidate requirements as per the listing. Then, determine if you meet those requirements. If you do, the logical conclusion is that you’d be a good fit for the job.

• **Making a decision on the job. **Sometimes you’ll need to make quick decisions on the job. For example, imagine you’re working in a food service role. You know that customers who like buying burgers also like to buy fries. If a customer is purchasing a burger, then, you can assume they might also like to purchase fries.

• **Arguments/Debates: **If you’re engaging in a workplace debate (a healthy one, of course), it’s best not to let emotion get in the way of your argument. Applying deductive reasoning to reach reasonable solutions together can be an effective way to remove emotion from the equation.

Time to put your deductive skills to use

Let’s recap on some of the key points:

• Deductive reasoning starts with a general premise and works from there toward a specific, logical, and true conclusion.

• Inductive reasoning is the opposite of deduction, starting with specific data and drawing generalized conclusions from that information, but it is more likely to lead to incorrect conclusions.

• Abductive reasoning is another form of thinking, which essentially takes an incomplete set of data and draws the best-educated guess from this information. It’s generally a good idea to validate your answers through another form of logic when using abductive reasoning.

• It’s generally best to use deductive reasoning where possible, because it typically offers more robust answers, with lesser risk of coming to incorrect conclusions.

Now, it’s time for you to start practicing your deductive reasoning skills and put them to good use!

And, while you’re at it, if you’re planning to use your deduction skills to find a new job, check out our Getting Hired Resource Center.