What Is Logic?

Transcript

[Presenter] What do you think of when you hear the word logic? Perhaps you think of Sherlock Holmes? A puzzle? Chess?

Strictly speaking, logic is the science of reasoning. It's not based on opinion or emotion. Instead, it involves seeking out evidence, looking at facts, and drawing reasonable conclusions.

You can use logic every time you are presented with an argument, or a piece of new information, to evaluate whether what you're being told is true or not. Logical thinking can be particularly helpful at work, because it allows you to make decisions and draw up strategies that are based on evidence rather than gut instinct, beliefs, or assumptions.

There are two main types of logic you can use to do this.

1. Deductive Logic

The first is deductive logic. This involves using general premises or statements you believe to be true, to draw conclusions.

For example, your first premise might be: "All spiders have eight legs." And your second premise might be: "A tarantula is a type of spider."

From this, you can form the logical conclusion that a tarantula has eight legs.

This kind of logic, however, only works if your premises are true. We could use the same system to argue something ridiculous.

For example, if your first premise was: "All grandmas have curly white hair." And your second premise was: "Andrea is a grandma," you could form the conclusion: "Andrea has curly white hair."

The conclusion is valid, logically, but we know that our first premise is incorrect, so this means our conclusion can't be correct either.

2. Inductive Logic

Another type of logic we can use to analyze information is inductive logic. Rather than forming specific conclusions based on premises, like inductive logic, this involves using observations, trends, and data to form general theories or conclusions.

While this may mean that the conclusions you form are not 100 percent true, they can still be considered educated guesses because they are based on evidence.

Observation

Inductive reasoning often starts with an observation. Say you're delivering some training at work. You observe that people are often full of energy in the morning, but become tired in the afternoon, causing them to lose focus. So you develop a theory...

Theory

You decide that, if you focus on heavy, detail-oriented learning in the morning, but introduce some practical, interactive exercises in the afternoon, people will stay energized throughout the day and learn better as a result.

Let's recap.

We need logic to analyze information accurately, to draw sensible conclusions, and to develop coherent strategies. There are two different types of logic we tend to use to do this.

Deductive logic involves focusing on widely-accepted facts to draw specific conclusions, while inductive logic means using observations and data to come up with general theories.

So, next time you have a problem you need to solve, think first about the facts. What facts could you call on to prove whether something is true or false? Then think about your own observations. Are there any trends that are happening? What does this mean? And what could a reasonable conclusion be? How could you test your theory using what you now know about logic?