Research
Philosophy of medicine: hierarchies of evidence, trials, diagnosis, and case studies in medical evidence.
Papers
The Pyramid Schema: The Origins and Impact of Evidence Pyramids
[This paper has been updated in 2026 from the 2022 preprint] Evidence pyramids are amongst the most recognisable artefacts of the Evidence-Based Medicine movement. Yet no study has established the origins of evidence pyramids, or analysed whether they offer any information beyond simple lists or tables. In this paper, I establish the origins of the first evidence pyramid and argue that the pyramidal turn is a retrograde step in evidence appraisal.
New publication: Grading evidence from qualitative research
Announcing a new paper co-written with a EULAR working group, reporting the findings of a systematic review of qualitative evidence appraisal tools.
[Superseded] The Pyramid Schema: The Origins and Impact of Evidence Pyramids
Evidence pyramids are amongst the most recognisable artefacts of the Evidence-Based Medicine movement. Yet no study has established the origins of evidence pyramids, or analysed whether they offer any information beyond simple lists or tables. In this paper, I establish the origins of the first evidence pyramid and argue that the pyramidal turn is a retrograde step in evidence appraisal.
The Machine Scientists: Iatrophysics and Selective Scientific Realism
The Machine Scientists - Giovanni Borelli, Jan Swammerdam and Niels Steensen - followed Rene Descartes in modelling the human body mechanically. The scientific success of this 'iatrophysical' programme, replete with rejected entities such as 'Animal Spirits', poses a problem for Scientific Realism. Using Psillos' moderate realism, this paper attempts to reconcile a selective realist position with the historical record.
Imitating Imitation: a response to Floridi & Chiriatti
In their 2020 paper, Floridi and Chiriatti subject giant language model GPT-3 to three tests: mathematical, semantic and ethical. I show that these tests are misconfigured to prove the points Floridi and Chiriatti are trying to make. We should attend to how such giant language models function to understand both their responses to questions and the ethical and societal impacts.
Minding the Gaps: Statistical Misrepresentation in Attainment Gap Research
Political interests configure the stories we tell with data. Closing the gap in attainment between disadvantaged students and their advantaged contemporaries is pivotal to an agenda to use education as a positive social force. But both the measurement and representation of this gap is politicised, skewed and open to manipulation. This paper shows how two organisations with inverse aims represent—and misrepresent—their measure of the attainment gap to portray diametric trajectories in the pursuit of equal attainment.
Causal Relevance (Philosophy of Diagnosis, Part 3)
This series of philosophical papers unpacks six philosophical issues in diagnostics and develops a pluralistic model of diagnosis. This paper analyses the role of causal relevance in diagnostics. Are diagnoses defined by their causal relevance to symptoms?
Pathognomy, Sine Qua Non and Constitutive Matching (Philosophy of Diagnosis, Part 2)
This series of philosophical papers unpacks six philosophical issues in diagnostics and develops a pluralistic model of diagnosis. This paper presents a set of minimal constraints which any theory of diagnostics must satisfy based on pathognomy and sine qua non relationships.
Problems of Diagnosis (Philosophy of Diagnosis, Part 1)
This series of philosophical papers unpacks six philosophical issues in diagnostics and develops a pluralistic model of diagnosis. This introductory paper outlines the six roles of diagnostics and distinguishes and relates the six problems of diagnosis.
The Dismal Disease: Temozolomide and the Interaction of Evidence
Evidence interacts. To understand the evidence base for an intervention we must look not only at individual studies, but the relationships between them.
The Authority of Evidence-Based Medicine
In the early part of the 20th century, the philosopher Ludwig Wittgenstein sought to demonstrate that metaphysical claims are meaningless. Statements which couldn’t be proven true in some way—through logic or evidence—weren’t even false, they had no meaning at all. But he ran...
The Positivity Machine: "Evidence-Based Alternative Medicine" and Grades of Recommendation
In his beat-poem Storm, the musician and comedian Tim Minchin lays out an apparent paradox. By his criteria, there can never be evidence-based alternative medicine. As soon as there’s evidence that a treatment works, it joins scientific medicine. Minchin goes on to list...
The Parachute Problem: Extracorporeal Life Support and the Demand for Trials
The United States Parachute Association recorded 120 deaths while skydiving in America in 2008-2015. Most were due to human error, while others resulted from collisions with other parachutes or aircraft. Only 5 were due to equipment failure. With around 3 million parachute...
The Avoidable Scandal: Benoxaprofen and Theories of Medical Evidence
Benoxaprofen, marketed as Opren in the UK, created a scandal in 1982 when it was withdrawn from sale amidst reports of over 60 deaths and thousands of adverse reactions. The question of who was at fault for this disaster has been addressed many times in the academic...
Pluralism and the Problems of Demarcation
In 1983, Larry Laudan proclaimed the “Demise of the Demarcation Problem” (Laudan 1983). I will argue that the ‘simple demarcation’ problem should indeed be abandoned. However, abandoning the quest for simple demarcation does not entail that demarcation problems are...
The Disunity of Evidence-Based Medicine
Critics and advocates alike have expended much effort defining Evidence-Based Medicine. However, there has been little consensus about what “Evidence-Based Medicine” is. Some authors see ‘EBM’ as something one believes—a view about medicine. Others interpret EBM as something...
Shorter pieces
Cultural Bias in Language Models: The Top 10 Test
How can AI-generated "Top 10" lists of cultural influencers expose the cultural biases and defaults that are built into our most popular language models? I propose and report an initial test using lists of the Top 10 most influential musicians.
Golem.AI: The Experimenter's Regress and AI Decision Systems
How can the concept of the experimenter's regress help us understand the problems in AI decision systems? I explore two forms of circularity that can underpin AI decision tools through the lens of Collins and Pinch's 'The Golem'.
'I did write that text': Ownership and Authorship Claims by Language Models
Will large language models acknowledge authorship of their own generated texts? Will a language model claim authorship or ownership of texts which it did not create? A mistaken comprehension of ChatGPT's abilities throws up a distinctive problem of intellectual property rights.
Perplexity, Creativity and the Zonkamoozle
What is the relationship between perplexity, creativity and novelty? Following on from 'Perplexing Perplexity', I set out to demonstrate that high perplexity texts are not always creative, and to showcase ChatGPT's ability to work with and even generate novel words - culminating in the Tale of Zonkamoozle.
Perplexing Perplexity
Detectors such as GPTZero use the property of 'perplexity' to try to detect AI authorship of texts. But I show that by writing in a specifically dull style, or engineering the prompt given to a language model, we can easily and systematically fool such detectors to label AI text as human and vice versa.
League Table Ranking and Name Recognition
Does the ranking of a UK university in league tables affect its reputation and name recognition? Using a novel data source from an online quiz, this research explores the complex relationship between league table rank and identifiability of universities.
Bias and the Myth of the Objective Average
Would you choose a black box AI surgeon with a 90% success rate over a human surgeon with 80% success? The answer exposes a fundamental and harmful assumption within dominant models of medical evidence.
The origins of evidence pyramids
What was the first evidence pyramid? A deep dive into the murky history of this novel way to present an evidence hierarchy reveals a significantly earlier origin that previously presumed.
Lumping and splitting: brain tumours in white Britons
A much-publicised report suggests that white Britons' brain tumour survival rates are lower than other ethnicities. But analysing the ethnicities categories used, and considering the diversity of the "brain tumour" label, complicates the picture, as the 'Dismal Disease' of Glioblastoma continues to confound.
On the Global Summit: do critiques of evidence hierarchies favour chiropractic?
The Global Summit systematic review claims that spinal manipulation therapy is not effective in preventing any non-musculoskeletal disorders. But a breakaway group has challenged their findings, in part based on my arguments regarding evidence hierarchies. Are they correct? Does my critique undermine the Global Summit review? If so, does the evidence base favour chiropractic?
Conversion Therapy: Evidence is Irrelevant
Pressure mounts upon equalities minister Kemi Badenoch to resign over the UK government's failure to ban conversion therapies. Attention has focused on the government's failure to publish research commissioned in 2018. But evidence about whether conversion therapy works is irrelevant: conversion therapy is not a medical intervention.
The Stochastic Masquerade and the Streisand Effect
What does Google have in common with Barbra Streisand? Since Google fired AI ethicists Margaret Mitchell and Timnit Gebru, our attention should turn to what they don't want us to read: "On Stochastic Parrots". Will the attempts to suppress this paper lead to it being overlooked, or will Google face Barbra Streisand's fate?
The True Causal Effect
Philosophy of medicine helps medical scientists to clarify their thinking. A maladept phrase like 'the true causal effect' serves to show why we need it.
195 Hierarchies: A Systematic Database Update
The database of evidence hierarchies has been updated based on a new systematic review of the medical literature, and now contains over 195 hierarchies.
5 years: Hierarchies of Evidence in Evidence-Based Medicine
In the five years since the publication of Hierarchies of Evidence in Evidence-Based Medicine, what has changed and what lessons can philosophers learn?
Are hierarchies history?
Even if the hierarchies of evidence are on their way out in EBM in theory, they could still be enjoying the spotlight in practice.
Dual Use Technology and GPT-3
Yesterday, AI researchers published a new paper entitled Language Models are Few-Shot Learners. This paper introduces GPT-3 (Generative Pretrained Transformer 3), the follow-up to last year's GPT-2, which at the time it was released was the largest language model out there....
Random Reflections: Cochrane and the Origins of Hierarchies
In 1972, Archie Cochrane publishedEffectiveness and Efficiency: Random Reflections on Health Services. In a little under 86 pages, Cochrane offers a wide-ranged but succinct delivery of his experience and his philosophy of evidence in clinical practice. It's a fascinating...
Crisis Thresholds: network demarcation and the Kuhnian turning point
In at least some of his work (e.g. 1962), Kuhn refers to a ‘crisis’ within the scientific community, which occurs when the build-up of anomalies becomes so substantial that most of the community begin to search for an alternative to the dominant paradigm. The crisis...
A Ghost of Progress - How Hierarchies Become Fixtures
I have written extensively on hierarchies of evidence in evidence-based medicine. The origin story of hierarchies of evidence is a little contentious. Several sources in EBM cite Campbell and Stanley's 1963 classic "Experimental and Quasi-experimental Designs for Research" as...
Stop Fighting, You're Making Me SAD
Does medical science have to be adversarial to make progress? Does progress in patient care consist of weeding out treatments which are ineffective and replacing existing therapies with new and better alternatives?
Echoes of Evidence
Do you have an idea of what makes good medical evidence in your mind? Do you have ideas about the kind of evidence you’d pay attention to, and the kind of evidence you can safely disregard? Or ideas about the evidence that would strongly sway your beliefs and actions, and the...
Medicine Needs Diverse Evidence
Do not centralize evidence. If you believe that all the evidence you need to make your decisions is of a single kind, you will be so much easier to mislead. Those who say 'I’ll believe it when I see this kind of study’, once their singular preference is declared, are so much...
Two Reactions to Philosophy in Medicine
I spend a lot of my time talking to healthcare practitioners of all kinds about evidence, formally and informally. I'm mostly focused on getting the word out that RCT results are not the only thing that matters in treatment recommendations, that hierarchies of evidence are...
UBL and Variation
I've argued that information about variation in treatment effects is vital for doctors, patients and regulators alike. This information does not come from RCTs. Nonetheless, we can acquire high-quality, compelling evidence of variation. The case studies I've presented in the...
Failures of Diagnosis
Of late, a confusion has emerged in the diagnostic and philosophical literature concerning the ways in which diagnostic failure can occur. It's rare to see clear attempts at a taxonomy of diagnostic failure. Here, I want to disambiguate a number of ways in which clinicians...
Hierarchies of Evidence: Database of Hierarchies
Hierarchies of Evidence are a tool employed by many advocates of Evidence-Based Medicine. They are used to appraise evidence from a range of sources, as well as to teach medical students about evidence and evidence appraisal. My PhD thesis concerns the variation in hierarchies defended, and the range of philosophical interpretations of those hierarchies.
Against "Effective Treatments"
I am agitating for philosophers of medicine and philosophically-minded clinicians to lead the charge against the term “effective treatment”. This phrase has become ubiquitous in the medical and philosophical literature. But it is a misguided choice which misleads the public...
An information ordering thing
Randall Monroe of xkcdstarted writing explanations of complex physical phenomena using only the most common 1,000 English words (or the most common 'ten hundred', as he'd have to put it). He recently released a straightforward application which allows writers to check which...
The Exhaustiveness Problem
Hierarchies of evidence can be classified as exhaustive or inexhaustive. A hierarchy is exhaustive if and only if it gives some ranking to any given piece of medical evidence - there's nothing it leaves out. But there's a dilemma which hierarchy authors face: either way,...
Two Dogmas of Evidence Hierarchies
Hierarchies of evidence in Evidence-Based Medicine (EBM) come in many varieties and have been very influential in medical practice and policy since the late 1990s. However, two fundamental problematic assumptions underpin the use of hierarchies of any kind in clinical...
An Honest Mess
Evidence-Based Medicine is an attempt to simplify and streamline a complex reality into a more manageable structure. Reflective EBM proponents know that matters are very complicated. But they understand that practitioners have very limited time (and abilities) to deal with...
Strength of Recommendation - the Rudner Problem
Strength of Recommendation hierarchies such as SORT and GRADE go a step further than your standard hierarchy of evidence. Standard hierarchies tend to rank or rate the evidence provided by a study on a scale of quality, strength or validity. Strength of Recommendation...
Ps in a POD - definitions in circles
In my paper "The Disunity of Evidence-Based Medicine", I lay out four distinct definitional strategies employed by proponents of Evidence-Based Medicine, each conveniently beginning with P: Platitude, Paradigm, Principles and Process. I made a bad pun about "Ps in a Pod" in a...
RCTs - a note on terminology
For the most part, when I'm talking about an RCT, it's understood as a Randomised Clinical Trial, though I use them interchangeably because I can get away with it - but not everyone can.