Isaiah Berlin (1909-1997), letter to Robert Wokler (July 10, 1972), in Building: Letters 1960-1975
, edd. Henry Hardy and Mark Pottle (London: Chatto & Windus, 2013), pp. 498-499 (at 499):
You really are more eaten with angst than almost anyone I know, and usually — though there are plenty of reasons for this, no doubt — without serious cause; just a mass of basic apprehension seeking to settle upon some appropriate subject for worry. For such a state I take a small valium pill — or half a one — and read articles in some encyclopedia, one by one in alphabetical order, until my sense of reality is restored. This was a treatment recommended to me by Aldous Huxley, and in my case it works beautifully. I hope it will in yours.
Hat tip: Ian Jackson.