this:'He got an atlas of the moon for Christmas and he read it like a storybook',and it never fails to bring tears to my eyes.Because the atlas of the moon is a storybook to those who are passionate about the landscape of the moon,and Maxwell's equations are to me as poetry,and did haunt me once as deeply as a good poem.I am often asked whether I feel divided between my scientific persona and literary persona,and the answer is a resolute 'no',and I think I have just explained why.Science and writing are indeed different adventures,but behind them both is the same need- the need to comprehend a little further,a little better the world within us as well as the world without. Para 9:So where do they differ then?In language,of course.Which brings me to my second point-language affects not just experience,but also comprehension.In the case of science,this comprehension is advanced by the lack of ambiguity-whereas in literature,it is often ambiguity itself that enriches our understanding of the human condition.I fear I have witnessed a drive towards the opposite in the last few decades-with literature or at least what passes for modern fiction,being judged increasingly in terms of its clarity and 'accessibility',and certain types of ambiguity being tolerated within science-both,for me,symptomatic of a laziness with which society seems to be afflicted at the present time.I will give you examples of both. Para 10:First,science.Here,I shall restrict myself to my own specialized field,because as Peter Doherty mentioned in his excellent lecture on Tuesday which some of you may have attended-we are all novices in every field but our own.My love affair with mathematics never ended,and eventually I found myself engaged in the rather peculiar act of using mathematics to understand infectious disease.This is for me a very rewarding business(and also pays the mortgage and the school fees)particularly as it combines my interests in biology and mathematics. So how do you use mathematics to gain insight into infectious disease? Para 11:So I use mathematics to generate testable hypotheses about infectious disease systems,and consider it to be an indispensable tool in the both guiding experiments and making sense of them later-a process that often diverges in its purpose as Peter explained so wonderfully well in his lecture. Para 12:More recently,an industry has grown in using mathematics to predict the future,a phenomenon that is not restricted to infectious disease but stretches widely into areas such an economic forecasting and the like.I have argued before,and will argue again today that this is an extremely dangerous and highly seductive territory,where the apparent rigor of mathematics can appear to lend an illusion of certainty,an illusion even of control.There are certain situations where the level of information surrounding a particular crisis is sufficiently detailed and explicit that intelligent mathematical models can provide some insight into future,if not current,methods of control.However,many do not fall within that category.I believe it is the duty of a scientist to be explicit about the assumptions that go into a mathematical model,and even more so of the limitations of the exercise-otherwise it constitutes,to me,a frank abuse of a process that relies on the lack of ambiguity Para 13:Having argued for the avoidance of ambiguity in science,it is only fitting that thethis: ‘He got an atlas of the moon for Christmas and he read it like a storybook’, and it never fails to bring tears to my eyes. Because the atlas of the moon is a storybook to those who are passionate about the landscape of the moon, and Maxwell’s equations are to me as poetry, and did haunt me once as deeply as a good poem. I am often asked whether I feel divided between my scientific persona and literary persona, and the answer is a resolute ‘no’, and I think I have just explained why. Science and writing are indeed different adventures, but behind them both is the same need – the need to comprehend a little further, a little better the world within us as well as the world without. Para 9: So where do they differ then? In language, of course. Which brings me to my second point – language affects not just experience, but also comprehension. In the case of science, this comprehension is advanced by the lack of ambiguity – whereas in literature, it is often ambiguity itself that enriches our understanding of the human condition. I fear I have witnessed a drive towards the opposite in the last few decades – with literature or at least what passes for modern fiction, being judged increasingly in terms of its clarity and ‘accessibility’, and certain types of ambiguity being tolerated within science – both, for me, symptomatic of a laziness with which society seems to be afflicted at the present time. I will give you examples of both. Para 10: First, science. Here, I shall restrict myself to my own specialized field, because as Peter Doherty mentioned in his excellent lecture on Tuesday which some of you may have attended – we are all novices in every field but our own. My love affair with mathematics never ended, and eventually I found myself engaged in the rather peculiar act of using mathematics to understand infectious disease. This is for me a very rewarding business (and also pays the mortgage and the school fees) particularly as it combines my interests in biology and mathematics. So how do you use mathematics to gain insight into infectious disease? Para 11: So I use mathematics to generate testable hypotheses about infectious disease systems, and consider it to be an indispensable tool in the both guiding experiments and making sense of them later – a process that often diverges in its purpose as Peter explained so wonderfully well in his lecture. Para 12: More recently, an industry has grown in using mathematics to predict the future, a phenomenon that is not restricted to infectious disease but stretches widely into areas such an economic forecasting and the like. I have argued before, and will argue again today that this is an extremely dangerous and highly seductive territory, where the apparent rigor of mathematics can appear to lend an illusion of certainty, an illusion even of control. There are certain situations where the level of information surrounding a particular crisis is sufficiently detailed and explicit that intelligent mathematical models can provide some insight into future, if not current, methods of control. However, many do not fall within that category. I believe it is the duty of a scientist to be explicit about the assumptions that go into a mathematical model, and even more so of the limitations of the exercise – otherwise it constitutes, to me, a frank abuse of a process that relies on the lack of ambiguity. Para 13: Having argued for the avoidance of ambiguity in science, it is only fitting that the