Julian Leslie has been publishing in psychology, behaviour analysis and related fields since 1972, and now has more than 150 publications. He obtained his doctorate from Oxford University in 1974 since when he has been in academic posts in Northern Ireland. he published textbooks in 1979, 1996, 2000, 2002 (the 1996 volume was reprinted until 2008 and remains in print, and the 2002 text also remains in print). As well as teaching undergraduate and postgraduate courses, he has successfully supervised 48 students who have obtained PhDs in fields including, experimental analysis of behaviour, applied behaviour analysis, psychopharmacology, behavioural neuroscience, experimental psychology, applied psychology. Three recent PhDs are concerned with behavioural strategies to address environmental issues. In 1977 he was co-founder of the group, Behaviour Analysis in Ireland which became a chapter of ABAI. In 2004, the group became the Division of Behaviour Analysis of the Psychological Society of Ireland, and he is currently the Division chair. He organised the Third European Meeting for the Experimental Analysis of Behaviour in Dublin, Ireland 1999, and has co-organised 13 annual conferences of the Division of Behaviour Analysis from 2007 to 2019. He was a keynote speaker at the European Association for Behaviour Analysis in Milan in 2006, and in Crete, Greece in 2010, and was a keynote speaker on behavioural strategies to address environmental issues at the Brazilian Association for Behaviour Analysis, Salvador 2011. From 1984 to 1994 he was head of the Ulster University Psychology Department, and from 2008 to 2015 was head of the Research Graduate School, Faculty of Life & Health Sciences, Ulster University. In 2013, he was a member of an international committee reviewing research in the Systems Biology Centre, University of Skovde, Sweden. In 2014, he was awarded a Doctorate of Science by Ulster University for career research on the experimental analysis of behaviour. From 2014 to 2019, he has given a series of papers on behavioural accounts of consciousness and the metaphysics of behaviour analysis. In 2018, he was made a Fellow of the Association of Behavior Analysis international, and was an invited speaker at the Sixth Sarasota Symposium on Behavior Analysis, an invited international speaker at the ABAI Convention, and an invited speaker at the 30th International Conference of the Spanish Society for Comparative Psychology.
Behavior analysis takes a natural science approach to human and animal behavior. Some basic tenets are widely agreed in the field but, arguably, some other assumptions are implicit in our approach and, if unexamined, may impair progress. Some of these are in the realm of metaphysics, that which is known a priori, and what can be deduced from what is so known. There is a strong Western philosophical tradition of naturalism and realism since the time of David Hume and these principles are embedded in the metaphysics of science and thus have been imported into behavior analysis. However, 20th-century American philosopher, Rorty suggests that these are not necessary truths but conventions of that philosophical tradition. Alternatively, we can adopt metaphysical assumptions that do not entail the familiar problems of dualism. Additionally, we have been constrained by some assumptions made by Skinner about the operant conditioning process which again are not necessary and may need to be discarded. Revising our metaphysical and theoretical assumptions, while retaining core principles which define behavior analysis, may enable us not only to resolve debates about private events, but also to provide accounts of interesting findings on animal cognition which otherwise pose problems for behavior analysis.