Logic For Dummies, 2nd Edition

Introduction

You use logic every day, and I bet you don’t even realize it. For instance, consider these examples of common situations in which you may use logic:

• Planning an evening out with a friend
• Asking your boss for a day off or for a raise
• Picking out a shirt to buy among several that you like
• Explaining to your kids why homework comes before TV

All these scenarios require you to use logic to clarify your thinking and get other people to see things from your perspective.

Even if you don’t always act on it, logic is natural, at least to humans. And logic is one of the big reasons humans have lasted so long on a planet filled with lots of other creatures that are bigger, faster, more numerous, and more ferocious. Because logic is already a part of your life, after you notice it, you’ll see it working (or not working) everywhere you look.

In this book, I show you how logic arises naturally in daily life. When you recognize this, you can figure out how to refine certain types of thinking down to their logical essence. Logic gives you the tools for working with what you already know (the premises) to get you to the next step (the conclusion). It’s also great for helping you spot flaws in arguments, such as unsoundness, hidden assumptions, or just plain unclear thinking.

About This Book

Logic has been around a long time — almost 2,400 years and counting! The ancient Greek philosopher Aristotle was the first to systematically study logic and attempt to formalize related ideas, ...