James Boswell portrait in the National Portrait Gallery, Edinburgh, Scotland. Boswell’s diary of Samuel Johnson has been called the greatest biography in the English language. I visited this portrait during my journey to Edinburgh in 2014 following the life and ideas of David Hume, my favorite philosopher, if I had to name just one. Boswell sat at the bedside of the dying Hume and marveled at his composure in the face of suffering and death.