In 1789 Jeremy Bentham published a book about utilitarianism. His ideas were further developed by John Stuart Mill who also published a book in 1863. This is when the utilitarianism theory became more known.

The noun utilitarianism is used as a subject or an object; for example:

Subject: Utilitarianism is included in this philosophy course.

Object: Part of this philosophy course covers utilitarianism.

fundamental and secondary utilitarianism

act and rule utilitarianism.

It collapses into Act-Utilitarianism.