Did he sound sceptical about this answer?
Well, you don't have to be sceptical about the answer to our quiz.
Hall was always among the first to identify key questions of the age, and routinely sceptical about easy answers.
In today's context, at the end of a week in which Hillary Clinton has yet again found herself face-to-face with a sceptical press demanding answers about her use of a private email address while working as America's top diplomat, her robust words almost two decades ago sound uncannily prescient.
You might think they'd be all in favour but David Cameron's green guru - Zak Goldsmith - is opposed and his Trade & Industry Spokesman, Alan Duncan, is sceptical and wants answers on cost and waste disposal.
"I am sceptical that the only answer is putting more guns in schools.
Contrary to the article by James Hansen, Kerry Emanuel, Ken Caldeira and Tom Wigley (Nuclear power paves the only viable path forward on climate change, 3 December), many scientists around the world remain sceptical that nuclear is the answer, or even part of the answer, to climate change.
Early in my business career which involved a lot of negotiations, I was cautioned to be sceptical about people who answered sensitive questions with the words "in actual fact".
For every sceptical query, he has a quotable answer.
It was hardly the answer to reassure a sceptical public.
