Brendan Clarke

Evidence-based medicine (EBM) makes use of explicit procedures for grading evidence for causal claims. Normally, these procedures categorise evidence of correlation produced by statistical trials as better evidence for a causal claim than evidence of mechanisms produced by other methods. We argue, in contrast, that evidence of mechanisms needs to be viewed as complementary to, rather than inferior to, evidence of correlation. In this paper we first set out the case for treating evidence of mechanisms alongside evidence of correlation in explicit protocols for evaluating evidence. Next we provide case studies which exemplify the ways in which evidence of mechanisms complements evidence of correlation in practice. Finally, we put forward some general considerations as to how the two sorts of evidence can be more closely integrated by EBM

The use of evidence in medicine is something we should continuously seek to improve. This book seeks to develop our understanding of evidence of mechanism in evaluating evidence in medicine, public health, and social care; and also offers tools to help implement improved assessment of evidence of mechanism in practice. In this way, the book offers a bridge between more theoretical and conceptual insights and worries about evidence of mechanism and practical means to fit the results into evidence assessment procedures.

Mechanistic philosophy of science views a large part of scientific activity as engaged in modelling mechanisms. While science textbooks tend to offer qualitative models of mechanisms, there is increasing demand for models from which one can draw quantitative predictions and explanations. Casini et al. (Theoria 26(1):5–33, 2011) put forward the Recursive Bayesian Networks (RBN) formalism as well suited to this end. The RBN formalism is an extension of the standard Bayesian net formalism, an extension that allows for modelling the hierarchical nature of mechanisms. Like the standard Bayesian net formalism, it models causal relationships using directed acyclic graphs. Given this appeal to acyclicity, causal cycles pose a prima facie problem for the RBN approach. This paper argues that the problem is a significant one given the ubiquity of causal cycles in mechanisms, but that the problem can be solved by combining two sorts of solution strategy in a judicious way

As the usual regulatory framework did not fit well during the last Ebola outbreak, innovative thinking still needed. In the absence of an outbreak, randomised controlled trials of clinical efficacy in humans cannot be done, while during an outbreak such trials will continue to face significant practical, philosophical, and ethical challenges. This article argues that researchers should also test the safety and effectiveness of novel vaccines in wild apes by employing a pluralistic approach to evidence. There are three reasons to test vaccines in wild populations of apes: i) protect apes; ii) reduce Ebola transmission from wild animals to humans; and iii) accelerate vaccine development and licensing for humans. Data obtained from studies of vaccines among wild apes and chimpanzees may even be considered sufficient for licensing new vaccines for humans. This strategy will serve to benefit both wild apes and humans.

Context: In this empirical and conceptual paper on the historical, philosophical, and epistemological backgrounds of second-order cybernetics, the emergence of a significant pedagogical component to Heinz von Foerster’s work during the last years of the Biological Computer Laboratory is placed against the backdrop of social and intellectual movements on the American landscape. Problem: Previous discussion in this regard has focused largely on the student radicalism of the later 1960s. A wider-angled view of the American intellectual counterculture is needed. However, this historical nexus is complicated and more often dismissed than brought into clear focus. Method: This essay assembles a historical sequence of archival materials for critical analysis, linked to a conceptual argument eliciting from those materials the second-order cybernetic concepts of observation, recursion, and paradox. Results: In this period, von Foerster found the “positive of the negative” in the social and intellectual unrest of that moment and cultivated those insights for the broader constitution of a new cognitive orientation. Implications: As a successful student of his own continuing course on heuristics, von Foerster left the academic mainstream to ally his constructivist epistemology with the systems counterculture

In this article, I begin by giving a brief history of melanoma causation. I then discuss the current manner in which malignant melanoma is classified. In general, these systems of classification do not take account of the manner of tumour causation. Instead, they are based on phenomenological features of the tumour, such as size, spread, and morphology. I go on to suggest that misclassification of melanoma is a major problem in clinical practice. I therefore outline an alternative means of classifying these tumours based on causal factors. By analogy with similar systems that have recently emerged for other cancers, I suggest that this causal classification is likely to be both workable and helpful, even in the absence of a full causal-mechanistic understanding of the aetiology of the tumour.