Just noticed on Twitter and on the BBC that the death of Nelson Mandela has been announced. In a world sadly lacking in genuinely heroic figures, he embodied in his very person and in the way he lived his life the notion of the 'philosopher king', being ruler, mentor, leader and guide to his people. A truly impressive human being and inspirational leader, he played a transformational role which required physical and moral courage and political insight and wisdom. To find any of these in a political leader is welcome. To find them all in one human being is little short of incredible. RIP Nelson Mandela. A rare man, incredible leader and truly impressive role model.