 As the head of PSI, Mason carried the torch for drug policy reform through a series of public appearances and televised debates and documentaries on drugs and their impact on society.Mason was a steadfast defender of the principle of cognitive liberty, and he made public statements in defence of the freedom of speech.When his friend, Michael Marlow, was charged with incitement for publishing a cannabis manual, Mason defended him by stating, “Here we are at the end of the millennium, and we are burning books.