# What is logic, and why does it matter?

## And can it make you rich?

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Logic is a means to arrive at truth. There are a variety of types of logic, but I’m going to look at the most basic of them, deductive logic.

This is not going to be a deep dive into the topic. We’re just dipping our toes into the shallow end of the pool.

To give the most **brief** presentation, and for **clarity** and **flexibility**, I’m going to bend some rules in the presentation, so if you are familiar with these rules, go easy on me. 😁 Everything here is valid, but to be rigorous you’d need more steps to work around the complexities. I’m just taking shortcuts.

To begin, an example:

Proposition 1: Gold bricks are heavy

Proposition 2: I am holding a gold brick (if only that was true, but let’s assume it is😁)

Conclusion: Therefore I am holding something heavy

That’s basically it! If you assume the propositions are true, then the conclusion MUST be true. Here is another:

P1: I am a Martian

P2: All Martians are blue

C: Therefore I am blue

Okay I admit it, I am not really a Martian. But that doesn’t matter in the slightest! If BOTH propositions were true, then the conclusion would be unavoidable.

Things can get more interesting. First of all, we can tweak the language a bit to make it sound more conversational.

P1: IF I am a Martian THEN I am blue.

P2: I am a Martian.

C: Therefore I am blue.

We can also make more complicated propositions and arguments:

P1: If I am a Martian AND I’m older than 20, THEN I am green.

P2: I am a Martian.

P3: I am over 20.

C: Therefore I am green.

There are “right ways” and “wrong ways” of doing this, but a moment’s thought should help decide which is which. Consider this one:

P1: If I am rich then I have money.

P2: I have money.

C: Therefore I am rich.

(Yay! I’m rich! Guess I’m outta here, see ya later!)

Nah, I’m not even close to rich, and you can see the problem. You can’t go from the end of the “if”…