Do you ever feel as though people just don't get you? That's kind of how David Hume feels about his moral theory. To him, it's super obvious that morality involves not just reason or rationality, but sentiment too—and he doesn't just mean sentiment as in getting teary-eyed over Bambi. What he means is that making a moral judgment or decision isn't the same as calculating a sum—there's way more to it than that.

Other people may argue that when it comes to morality, reason isn't just a piece of the pie; it's the whole darn thing. For Hume, though, this is just the beginning: it lays the groundwork, but it's not the whole shebang. We don't just think something's right or wrong; we feel it.

Hume thought this was clear enough, but, apparently, other philosophers in his day didn't see it that way. In fact, one of the reasons why Hume wrote this book was to set the record straight. Not only did Hume see some of the existing theories as confusing and out of touch, he believed they put way too much emphasis on reason and completely snubbed sentiment.

But, wait, there's more: Hume was peeved that some of these theorists saw human beings as totally selfish. Sure, we care about ourselves, but why can't we care about others, too? Why does this have to be an either/or scenario? No, Hume wasn't buying it.

This wasn't the first time that Hume had tackled this subject: he'd discussed it before in "Of Morals," which was part of his A Treatise of Human Nature, published in 1738. Unfortunately, the public reception to this work wasn't so hot, which was why Hume set about making his stuff more accessible.

Fast-forward a few years to 1751 and voilà! An Enquiry Concerning the Principles of Morals was born.

You know the phrase "don't judge a book by its cover"? Well, we can say a similar kind of thing about this text. Eighteenth century? Philosophy? Long, serious-sounding title? Let's be real—it doesn't exactly scream "must read." But stick with us because it's way more relevant than you might think.

Some things may have changed since Hume's time, but one thing that hasn't is the importance of morality and ethics in our lives. We may not think about it every day but, sometimes, when we're faced with a difficult decision, we realize how epic this subject can be.

Morality isn't just about the big decisions, though. Hume talks about things like kindness, honesty, politeness, loyalty, justice, property... if we look at it this way, we can see just how important a role it plays. Even if we don't think about it 24/7, it's part of who we are and how we act.

Philosophy may have a reputation for being stuffy, but some of the most popular movies and TV shows of our time like to chew on philosophical questions: the debate about cloning in Jurassic Park, Spock's "the needs of the many outweigh the needs of the few" line in Star Trek, Peter Parker learning that "with great power comes great responsibility" in Spiderman. And that's just for starters.

From Buffy to The Simpsons, moral philosophy is a big deal. So check out Hume's Enquiry for the lowdown on just how essential it is to our lives—we promise you won't be disappointed.