John Stuart Mill (1806-1873) was an English philosopher and economist. He wrote one of his most famous essays, &quot;On Liberty&quot;, in 1859.<br /><br />&quot;On Liberty&quot; is the philosophy classic that laid the foundation of modern liberal politics, by applying the concept of utilitarianism to societies and countries, in order to create a working system between authority and liberty.&nbsp;<br /><br />It was widely read at the time, and in the century and a half since it was published, it has proven to be one of the most influential books of political philosophy of all time.