Let us start with one hypothetical.

Suppose you were walking down the street in no particular hurry, and you found someone who was dying. Suppose you had a cell-phone, and it would cost you a small amount to call an ambulance. Do you have an obligation to do so? Have you committed a crime if you didn't do so?

If you tell the person that you will do so, then you have deceived them. If there is a crowd of people, and you announce that you are calling for help, and then fail to do so then you have put the person at risk by lying. Others will not call for help because they thought you would. Likewise if the person is an employee or a friend or one of your students or a child then you may have a duty of care, but the hypothetical is different here.

The essence of the question is this: do you have a duty of care to a complete stranger? If so, is this duty a moral duty or a legal duty or both? Should someone who refuses to help be charged with a crime? If so, what should the crime be called?

Now let us consider a second hypothetical:

Suppose the stranger in question is about to suicide, but you can stop them from doing so with no risk and little cost?

Does change the morality or legality of the situation?

Now let us consider a third hypothetical:

What if the person is not at risk of dying, but about to suffer a permanent injury.

Does the situation change?

And a fourth:

What if the person is at risk of suffering prolonged physical or emotional discomfort.

What are your obligations then?

Internal inconsistencies aside, someone's answers to these four hypotheticals tells us most of what we need to know about their fundamental morality.

The libertarians amongst us would say that your only duty to another is to not initiate force against them. Hence you have no obligation to help a stranger.

The humanitarians would say that you have considerable obligation to the stranger - not only responsibility for their life, but for their comfort and possibly even their happiness.

Morality has no objective justification. It is a useful concept because it allows the framework for people to explore common beliefs and values.