Utilitarianism is a philosophical essay written by liberal English philosopher and political economist John Stuart Mill that was published in 1861. Mill, whose influence on thought in the 19th century was vast, wrote the essay to provide support for the value of utilitarianism as a moral theory, and to respond to misconceptions about it. Mill defines utilitarianism as a theory based on the principle that “actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness.”
The theory of utilitarianism has been criticized for many reasons. Critics hold that it does not provide adequate protection for individual rights, that not everything can be measured by the same standard, and that happiness is more complex than reflected by the theory. Mill's essay represents his attempt to respond to these criticisms, and thereby to provide a more complex and nuanced moral theory.
Read the overall summary and discussion of how Mill presented the differences between ethics and behavior in Utilitarianism. Or, learn more by studying SparkNotes guides to other works by John Stuart Mill.