As you’ve gathered by now, morality is the sort of thing that isn’t testable by science. There is no scientific instrument that measures moral rightness or wrongness. So you’ll have to decide what’s reasonable to believe. Probably, you already have some beliefs in your worldview about what you should and shouldn’t do. Maybe you just remember what your parents told you when you were young, or maybe you just follow the laws where you live. But the problem is that those ways of determining what’s right and wrong will only get you so far. What will you do when you’re confronted with a moral choice that isn’t covered by the law, or that your parents never mentioned?

The philosophy of morality is not so much about which actions are right and which ones are wrong, as it is about what makes actions right or wrong. The central question of moral philosophy is “where does morality come from?”

You may never have thought about why you think some actions are good and others are bad, but I’m sure that hasn’t stopped you from knowing the difference when you see it, so how do you determine whether an action is right or wrong, good or bad? I suspect you have some sort of system for deciding. Everyone does. Maybe it’s a set of rules, maybe it’s a gut feeling, maybe something else. 

Where do you get your beliefs about morality? In other words, where do you believe morality comes from? Here are some possibilities.

Culture

Certainly some people probably believe that morality comes from culture, that whatever is commonly accepted in their culture is right, and whatever is commonly forbidden is wrong.

Religion

In a way that’s similar to culture, some people believe that actions that are permitted by their religion are good, and those that are forbidden by their religion are bad. On their worldview, if someone with this view wants to know whether an action is right or wrong, they can just consult their religion’s sacred texts, or a religious expert.

Feelings

Probably a lot of people think that morality comes from inside themselves. They could claim that they have certain emotional reactions to actions, and those feelings determine what is right or wrong.

Pain and pleasure

This is a simple system for determining what is right or wrong might consider only the pain or pleasure that actions produce. Actions that produce pain are wrong, and actions that produce pleasure are right.

Interests

Everyone has interests—things they care about—and it would be reasonable for someone to say that they should only have to be concerned with the things that they care about, and that benefit them.

Rationality

Someone could say that morality comes from rationality, so whatever is rational is right, and whatever is irrational is wrong.

Rights

Maybe you believe that everyone has certain basic, natural rights, and upholding those rights is good, while violating them is bad.

Relationships

The most important thing to some people is their relationships with others and the bonds of care between them. For them, good actions are ones that promote and sustain those relationships, and bad actions are ones that damage them.

Character

You might believe that what makes an action right or wrong has to do with the person who does it. Maybe you believe that good people do good things, bad people do bad things, and it’s the character of the person doing the action that makes it right or wrong.

Try asking some people you know. See what they say. It’s likely that they will give some version of one of those answers.