Why is logic useful?

Ordered Thinking

If you are wondering what you can do with logic, the answer is that logic can do something with you. But what is Logic? Logic builds the mental habit of thinking in an orderly way, it can be described as reasoning conducted or assessed according to strict principles of validity. Even if you forget the details of a lesson in logic, you will become more habitually aware of the structure of logic, just as you are aware of a second language after forgetting the details of its grammar or some of its vocabulary. Logic studies the structures of thought. Just as objects in the material universe, thoughts have structures too. Thought is not a blank screen, receiving its form only from the world that appears on it.
No lesson is more practical than one in logic, for no matter what you are thinking about, you are thinking, and logic orders and clarifies your thinking, no matter the content of your thought. The principles of thinking logically can be applied to all thinking and to every field.

Power of Proof and Persuasion

Any power can be used or abused. The power of logic is rightly used to find truth and rectify errors; it is wrongly used to win arguments and defeat our opponents. 

Reading 

Logic is a tool that is used across disciplines. You are always going to be reading books or listening to lectures, podcasts, speeches, and logic will help you think more clearly and effectively when you read, listen and learn. It is not a far-stretch to speculate that one of the biggest reasons for the steep decline in our reading ability is the decline in teaching of traditional logic. 

Writing

Clear writing and clear thinking come in a package. The presence or absence of either one brings the presence or absence of the other. Muddled writing fosters muddled thinking, and muddled thinking fosters muddled writing. Clear thinking fosters clear writing, and clear writing fosters clear thinking. 

Testing Authority

We need authority as well as logic. 

We need authority because no individual can discover everything on their own. We all have to rely on expert consensus when it comes to physical sciences and other scientific disciplines. However, we need logic to test our authority. There is another reason we need logic when it comes to authority: we need to have good reasons for believing authorities, for in the end, it is the individual you who decides which authority to trust.

Reducing Uncertainty 

Formal logic guarantees absolute certainty. However, formal logic is not the focus of this chapter. We focus on informal logic, which is of more use when it comes to our daily lives. But informal logic cannot guarantee absolute certainty. Unlike formal logic, informal logic aims to reduce uncertainty and guarantees higher degrees of accuracy. 

Wisdom

Philosophy means ‘the love of wisdom’. Etymologically speaking, the term comes from the Greek words philos, meaning friend or lover, and sophia, meaning wisdom. Although logic alone cannot make you wise, it can help. For logic is one of philosophy’s main instruments. Logic is to philosophy what telescopes are to astronomy or math is to physics. A quintessential stepping stone which should not be avoided.