I have not been quite clear whether I am regarded primarily as a biologist or as a psychologist by my fellow members of this club. I have been a professional biologist, with comparatively short intermissions, for nearly 40 years, but I am not and have never been an experimentalist in the ordinary sense, though in [Thomas Dewar] Weldon’s sense I might perhaps put in a claim to the title. And this not because I do not fully realize the immense value to biology of the experimental method, by which I mean the deliberate controlled interference in the ordinary course of nature for the purpose of getting nature to answer questions that have aroused our interest or on subjects on which we have formed theories. On the contrary, I am convinced that real progress in biology depends very largely indeed, if not almost wholly, upon experiment in this sense, and it is a conviction that increases with the years. I have not been an experimentalist because I have little natural love for experimentalism and I have found more than enough to do in other fields. But in thus neglecting experiment I fully realize that I have missed the chance of contributing humbly to the progress of biology in any significant sense, though this does not in fact greatly distress me. In psychology, I am merely an amateur. As an undergraduate, I took my share of the usual interminable discussions on the universe—on philosophy, psychology, religion, politics, art, and sex. I was mildly enthused by the work of William James, particularly by the Principles [James 1890], and I read or dipped into various other psychological works, but I made no serious study of the subject. It was not until I was past 35 that I was introduced to modern psychopathology by my friend Bernard Hart [1912], one of the pioneers of the subject in the country. He failed to get me interested in [Pierre] Janet’s work [1907], but succeeded quickly enough with Freud’s, in which he was profoundly interested and which he was trying out in the asylum where he was a medical officer. From that time onward, my interest in psychoanalysis steadily grew, reaching its highest pitch of intensity during the war, when I read all of Freud’s more important works. Later on, I spent 9 months altogether with Freud himself and even, on his advice, myself conducted an experimental analysis, lasting nearly 2 years, on an obsessional neurotic. Since then, my interest in the subject has remained untouched, together with my conviction of the essential truth of Freud’s main conclusions, though I believe some of them require restatement. In 1926, it was touchand-go whether I became a professional psychoanalyst or took my present job. I still keep in touch with psychoanalytic circles, though it is rather a light touch now, moving to preoccupation with professional work. In philosophy, I am not even an amateur but just an ignoramus. It is true that during my undergraduate days I was a close friend of Bertrand Russell, who read philosophy at the same time as mathematics, and it would be difficult to estimate what I owe to the constant intercourse with his singularly acute mind. But I could never make much headway with such serious philosophical books as I tried. And the result, of course, is that I do not know my way about the subject and am quite likely to make the most elementary blunders through sheer ignorance, or on the other hand to imagine that I am stating something of real importance when it is in fact a mere commonplace of the textbooks. And yet I clearly must invade the region of philosophy if I am to try to make any contribution to our discussions. Ecosystems (2002) 5: 614–624 DOI: 10.1007/s10021-002-0223-4 ECOSYSTEMS