The methods of philosophy may be ancient, but they remain as relevant as ever when it comes to life's difficult questions. In moral and political philosophy, the aim is to study difficult and complex problems about ethics and justice. Professional philosophers are paid to grapple with these questions, but the really practical questions of ethics belong to everyone.

Many of these questions are ones that I'm now exploring, with colleagues from around the philosophy profession, in the new ABC series Ethics Matters. It looks at some of the thorny questions we face in modern Australia.

Here are just five modern-day dilemmas that can benefit from a more philosophical approach.

Am I entitled to my opinion?

We all like to be free to say what we think – nobody should have the right to censor us, or to threaten us with harm if we don't shut up. At the same time, most of us would accept that context matters, and that what some people say can cause harm to others.

Is this ever a good reason to command anyone to stay silent?

One place to start is by asking why freedom is worth having in the first place. Philosophers have long defended free speech on grounds that a society that protects new ideas will do better in the long run.

This is because what's worth having is not merely free speech, but rather something like the free exchange of ideas, so that different perspectives can be put to the test. The poor track record of totalitarian regimes suggests that this way of thinking has something going for it.

Applying this perspective, we might then ask about what counts as 'speech' in the first place?

Some people would like to see restrictions on violent video games, and pornography. If these don't contribute to an exchange of ideas, then perhaps there is a case for distinguishing these forms of expressions from those where someone is trying to make a serious point, even if others find it difficult to hear.

While there will always be disagreement about particular cases, we might still draw the conclusion that an entitlement to say what one likes comes with at least some obligation to try and defend it.

After all, why should you be entitled to say what you think if all you expect is for others to agree?

To buy or not to buy?

Think about the last item of clothing, or electrical gadget, you bought. How much do you know about its supply chain? What kind of people made the products you own, and how much were they paid? How about the conditions under which they worked?

Chances are you know little or nothing about where the item comes from, how it was made, and by whom. And that goes for most consumers today.

In a globalised world where supply chains reach all around the globe, it's almost impossible to know the stories behind the assembly of all the items in your wardrobe and office. And yet, it is remarkably easy to get a very general sense of what goes on elsewhere so that consumers in wealthy countries can get what they want, for cheap.

We all know about fires in India's textile factories, and the low wages paid to those working on China's laptop assembly lines.

Given our general awareness of these facts, is it wrong to buy a product whose production probably depends on harsh conditions further up the supply chain? Should we, for example, boycott products until those selling them provide assurances about how they were made, even if that bumps the price up a bit?

Or should we keep buying? After all, boycotting a product may just put workers out of a job. How do we find the middle ground?

There's no easy answers, but asking the questions in the first place can broaden awareness for consumers in Australia.

Who gets to come into the country?

While he was Prime Minister, John Howard said that "we will decide who comes to this country and the circumstances in which they come." Many people agree, and most countries in the world put this idea into practice when controlling their borders.

But what are the actual arguments for why a country should have an entitlement to keep people out, particularly people in great need?

It's tempting to draw analogies between whole countries and smaller groups: think about a footie team faced with a number of players desperate to be drafted, or a university admitting students. In each case, an organisation has the right to say 'no' to outsiders who want to gain entry. Footie teams and universities have an interest in shaping their own identities and pursuing certain standards. This gives them a right to have some control over who gets to join. Are countries the same?

We can make progress by asking: what kind of thing is a country anyway? Are we really in control in the first place, like a footie team controls its squad, even if we keep migrants out? Australian culture, like most other cultures, has always absorbed foreign influences like music, film, sports, and food. And a culture is always a work in progress. So if things are going to change anyway, and in ways we can't really predict, then why not let them change by letting people in?

Applying a philosophical approach will help us work out exactly what entitlements a country has, and why. We will move beyond analogies with sports teams and other smaller groups, working out what truth is in these comparisons and what makes them misleading when accepted uncritically. Only then will we make progress towards a less simple, but probably more plausible answer than the slogans we get from politicians.

When to blame and when to forgive?

Suppose someone wrongs you. There are two things you can do in response – you can be angry and treat the perpetrator in a way that reflect this, or you can forgive them and treat them as you might have done so before they did what they did. Very often, we go with the first option for a while before moving onto the second – we blame, and then we forgive.

This raises an important set of philosophical questions about the benefits of this process, and what requirements should govern it. Can forgiveness ever be premature, or conversely, withheld for too long? Is blame supposed to trigger a response, such as repentance, that then justifies forgiveness? Does this mean that it is incoherent, or even wrong, to forgive people who do not repent, or who die before getting the chance?

Some Holocaust survivors say they forgave their Nazi persecutors, while there are those of us that continue to feel resentment about having been wronged in comparatively trivial ways. Theorising about the conditions under which forgiveness is appropriate will tell us which party, if either, is behaving appropriately.

Forgiveness and associated ideas like blame play a central role in our institutions as well as our private lives. Figuring out what forgiveness is for, and when it should be given, promises to tell us something about the purpose of criminal justice, and what limits might be put on, say, the amount of time we put someone in prison.

In this way, thinking about forgiveness promises to enrich our understanding both of our personal lives, and of our institutions.

Whose social norms?

It's easy to think of examples of customs or patterns of behaviour from other societies that shock us deeply. We are appalled by the way in which certain communities execute female family members for sexual 'transgressions', cut the genitalia of very young girls, and subject homosexual men to public executions.

In Australia, and other Western countries, we like to think that we are free individuals. To some extent this is true, but we're also enormously conformist.

Take a look at what you're wearing, and think about what sort of hairstyle you have, and whether you have worn makeup today or would never dream of wearing it. One of the reasons you conform to norms like this is that they carry costs of noncompliance. These costs vary according to our goals, jobs, and overall social position, but they're always there. And we generally, if unconsciously, make sure that we behave in ways compatible with them.

What this means is that when social norms appal us, we should realise that those who obey them are typically conforming, just like we in Australia do, albeit with higher stakes. Not conforming can lead to ostracisation, sometimes for entire families, which can then impact on the next generation when trying to find spouses of their own. Strange as it may sound to us, conformity, hard as it may be, can still be the rational choice.

Appreciating this helps us understand an important difference between ethics and justice: sometimes the person is acting in ways that do not betray a bad character, but rather an oppressive structure.

Practices such as 'honour killings' are barbaric, but they are structural injustices, not isolated personal failings. How often do we condemn or shame people in Australia for not behaving in ways that are ultimately about conforming with our structures?

Thinking and talking about morally difficult questions tends to raise passions, particularly when we encounter disagreement, as we almost always do.

Reasoned argument is the way out of this, if not to eventual agreement then at least to a better understanding of each other's perspective and why our disagreements can be so persistent. In this way, the discipline of philosophy can actually make our lives in this hectic world easier, and help us get along – just so long as we are prepared to talk about it.

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