What makes a crime?

This video is about the theoretical background behind the criminal legal system. I look at what makes a crime and three main philosophical foundations: legal moralism, the harm principle and paternalism.


A crime is an offence punishable by law. Arguably there are two reasons for criminalising an act or creating a crime:

1. The conduct itself is wrongful

There are three central arguments that make a conduct wrongful:

i. Legal Moralism

Lord Devlin in “Morals and The Criminal Law” 1959: immorality is what every right-minded person is presumed to consider immoral.

He argues that ‘immorality’ is a necessary and sufficient condition of criminalisation.  This view is based on the premise hat social harmony is jeopardised if morality is not underwritten by the law.

He argues that morality forms a ‘seamless web’. By this metaphor, he intended to convey the notion that ‘society’s morals’ form a fragile structure and that is morality is not reinforced legally, then damage to the entire structure will follow.


Rejects rationality, doesn’t look at an empirical investigation of the effects of criminalisation, based it upon feelings.

Bentham warned us to be suspicious when officials claim they are acting in the name of ‘right minded people’. In many cases it just justifies the prejudices of legislators themselves and is dangerous.

Seamless web is also problematic as Hart points out people don’t abandon their moral views if they are not punished by law itself.

ii. The Harm Principle

People should exhibit free will and the state should only intervene if harm is caused to others.

The problem is, is this primary harm e.g. assault or secondary harm e.g.  seat belts

The Report on the Wolfenden Committee on Homosexual Offences and prostitution 1957 argues that the law is to intervene to protect vulnerable people and preserve public order but not to intervene in private lives of citizens or enforce any particular pattern of behaviour. The Committee was recommending that homosexual behaviour between consenting adults in private should no longer be a criminal offence.

The principle was famously articulated by J.S.Mill as “the only purpose for which power can be rightfully exercised over any member of a civilised community, against his will, is to prevent harm to others’

Harm is to be understood not just as physical harm but a violation of any recognised interest.


Is that if you are focused on only harm to others it becomes impossible to criminalise drugs or the wearing of seatbelt.

However, many modern harm theorists point out they would support it because it is potentially harmful to others. Kaplan explains that there are different categories of harm such as ‘public ward harm’. That is, he may impose on other the cost of rectifying the damage he causes himself. He may not be able to take up the economic responsibilities he owes others as a result . Furthermore, other individuals may copy the behaviour and suffer harm as a result.

However, this is still problematic because if we acknowledge the broad concept of harm, there are few actions that one can perform that threaten harm only to oneself. Thus leading to a world where almost all acts are criminalised.

Prohibition of harmful conduct may in itself result in harmful consequences such as the sale of say drugs may indirectly or directly harm consumers as well as the potential economic harm to business enterprises involved.

Bentham advocated a utilitarian outlook.

iii. Paternalism

Preventing someone from harming themselves – inferring with autonomy for their own good.

2. It is necessary to employ criminal law to prevent such conduct.

– This refers to the principle of minimising interference in an individual’s autonomy.