The historian Piers Brendon asserts that Burke laid the moral foundations for the British Empire, epitomised in the trial of Warren Hastings, that was ultimately to be its undoing: when Burke stated that "The British Empire must be governed on a plan of freedom, for it will be governed by no other", this was "...an ideological bacillus that would prove fatal. This was Edmund Burke's paternalistic doctrine that colonial government was a trust. It was to be so exercised for the benefit of subject people that they would eventually attain their birthright—freedom". As a consequence of this opinion, Burke objected to the opium trade, which he called a "smuggling adventure" and condemned "the great Disgrace of the British character in India".
What did Burke say the plan of freedom must be governed by?