41 programming. I built my first home computer around then too. So I guess I was always tinkering away at the edges of technical science.
ausdoc. com. au 19 SEPTEMBER 2025
41 programming. I built my first home computer around then too. So I guess I was always tinkering away at the edges of technical science.
AD: You have a deeply intellectual background, but did you find anything about the college fellowship challenging?
Professor Shrapnel: No, I didn’ t really. I was seven months pregnant when I sat the exam. But I’ m one of those people who thrives on learning. I’ m happiest when I’ m on the steep part of a learning curve. With your exams, you’ ve done all your rotations and you’ re just pulling it all together. So, no … not really.
AD: But then in your early 40s, you decided to enrol in a philosophy degree. Why was that?
Professor Shrapnel: So what happened was I’ d been working away in general practice, and I always knew that I missed the cutting-edge research … There is some opportunity for deep thought, but it’ s reasonably limited.
And my children, I’ ve got two boys, they were both at school and I just suddenly felt like I had a bit more space in my brain.
Karl Popper.
I was also fascinated by my GP experience talking to patients and often giving them a distilled version of a very complex scientific explanation.
I was interested in the nature of scientific explanation and what is it that makes us believe that the explanations we give people are true, that science is true and that medicine works.
And so I started reading about the nature of scientific explanation and justification theory.
AD: This sounds like the philosopher Karl Popper, but you mean more than that?
Professor Shrapnel: Karl Popper is a great place to start. There is a long philosophical tradition on the nature of scientific explanation and belief justification.
And I started investigating that myself. I ended up back at the University of Queensland looking at philosophical theories of explanation and scientific realism. A lot of the theories made sense, but they all began to break down when it came to quantum theory or quantum physics.
AD: And you’ re not saying this because you can’ t prove quantum theory false, one of the necessary conditions for a scientific theory— that you could in theory prove it wrong. You are talking about something different. This is about reality?
Professor Shrapnel: Probably the easiest way to describe it is that many theories of explanation have at their heart the fact that what we desire are causal explanations.
So explanations where we’ ve got some kind of cause-and-effect relation. We say A causes B and that’ s why we believe that this is true. And it’ s the case in medicine. We believe bacteria cause infection, and we believe that because of the causal links we identify through experiment and observation.
Quantum theory throws our understanding of cause-effect relations out the window.
AD: I understand there’ s still a debate around whether quantum theory directly reflects reality or whether it’ s just an effective mathematical tool for predicting experimental outcomes.
Which side are you on? Is the reality as bizarre as quantum theory suggests?
Professor Shrapnel: I think it’ s like Aristotle says: the truth is somewhere in the middle.
AD:( laughing) You can’ t say that. That’ s a cop-out.
Professor Shrapnel: I think 100 % that it’ s a mathematical tool which we use to describe reality around us.
But you can’ t just say that’ s all it is because then you’ re left with the question of why it works so well. What is it about reality that ensures the tight correspondence between the mathematical recipe we use and the way nature seems to work?
A lot of my research actually is in trying to understand what the mathematical axioms of quantum theory are telling us about the nature of reality.
The way I currently tackle the problem is to ask if we can start from core principles that we believe about the nature of reality and then
reconstruct the mathematics of quantum theory from that?
AD: In terms of explanations and justification, it must be difficult for doctors when talking about risks and outcomes that most patients don’ t understand confidence intervals for instance.
Not that the mathematical ideas are beyond them, but it’ s like Stephen Hawking’ s A Brief History of Time. He was told that for every equation he put in the book, the readership would halve.*
So my question— would life as a doctor be easier if you could talk about P values and confidence intervals and the mathematical reasons why screening tests are not always the wonder that a lot of people think they are?
Professor Shrapnel: I think yes and no. It would be a lot easier if patients understood the basis of statistics, but of course, but P values don’ t tell you everything.
That’ s one side of it. But part of our task as GPs is to act as the experts and provide advice without necessarily requiring our patients to do a medical degree or a statistics degree.
As GPs we develop techniques like giving analogies because we know all humans are very bad at estimating probabilities and the likelihood of poor outcomes. People will generally take a risk for a good outcome at a very low probability.
But at the same time, they won’ t accept that same low probability for a bad outcome.
So you say things like,‘ There are no guarantees, but if it was my mother I’ d suggest that she does this, or if it was me, then yes, I’ d take the medicine.
‘ There are always risks and we can’ t guarantee that this won’ t happen or this will happen, but on balance, it’ s what I would be doing.’
AD: Do you think there is a weakness here? The relationship with the patient relies on trust. But if it’ s solely trust, as we see with vaccines, it can be dismantled by others mimicking the approach you take as a doctor?
Professor Shrapnel: It’ s one of the areas of general practice that I always found really difficult. And as a junior doctor, you start by not doing that. You give the patient every bit of information you possibly can, but you overwhelm them with information and then tell them that it’ s up to them to make the decision.
In a sense this ends up potentially robbing them of the known positive effects of the placebo effect! But in a way, you also undermine that sense of trust. You are not presenting yourself as someone who’ s prepared to take
I became much more honest about the unknowns. Medicine is not black and white.
responsibility in a way— I don’ t know, it’ s very difficult to explain it.
It’ s one of the hardest things about being a GP. But definitely over my career as a GP, I’ ve changed my attitude.
I became much more honest about the unknowns. Medicine is not black and white.
So I will say,‘ I can’ t put my hand on my heart and tell you that something that’ s unpleasant will definitely not happen here. But on balance, I think it’ s probably the best thing that you can do because of these reasons.’
And I think, as long as you are honest and document things carefully, that works. But I take your point. The biggest threat to general practice is that degradation of trust by elements outside our control.
One of the things about medicine is that we’ ve got evidence at all levels of enquiry— at the level of genes, cells, the immune system, at the physiological level, at the gross patient level, at the population level, etc.
There’ s nothing from what we currently know that is pointing to an alternative direction than the scientific method that we apply to making decisions in modern medicine. And so it seems the sensible course to take. I think the other thing I would say to people is,‘ Look, if you were in a car accident and you were bleeding to death, you would go to a hospital and be treated by a doctor.’
AD: An emergency focuses the mind, even if it won’ t always change it.
Professor Shrapnel: Look at child mortality in the 19th century; look at the number of women who died in childbirth. We’ ve made such incredible progress in so many areas, regardless of how you think that it works, there’ s a lot of evidence that medicine and the scientific method works.
AD: There is another message underpinning your life story. It helps show female doctors that having a career in medicine,
Associate Professor Sally Shrapnel( right) with Brisbane psychiatrist
Dr Helen Siddle, in the 1990s.
having children and a family, there is still a world beyond to be explored.
Is that a fair description?
Professor Shrapnel: The point is that we should not be afraid of career change at any stage in our lives. That applies to all of us, not just women.
We are brought up to believe the myth that there is some age limit on your ability to learn new things and be creative.
And I just think that that is a myth. As doctors, we are all pretty turned on by knowledge and learning. We wouldn’ t have made it through medicine if we weren’ t.
And that actually re-engaging with learning pathways once your family is at a certain stage, or even just once you are older, is reinvigorating. We need to be reminding people of that, because I think we get caught up in the sunkcost fallacy too and don’ t feel we can or should change.
I had plenty of people telling me,‘ Sally, you’ ve invested so much time in medicine and becoming a doctor, and all that training and all those exams, how can you possibly look at another career?’
But you don’ t lose. You still have your training and your experiences.
AD: Maybe that makes my last question slightly redundant. I mean, you will never rule out going back to general practice?
Professor Shrapnel: Honestly, I miss seeing little kids. I miss the antenatal care. There’ s a lot of general practice that I miss.
I’ ve been out now for a long time, but I’ ve spoken to my bosses at uni and asked if there is scope for me to go back, just initially one day a week, and see how that goes. And they’ re very supportive of that. Who knows what will happen? I know at some point I’ ll go back, even if I just take a two-year sabbatical and take leave and do it.
* Stephen Hawking ended up including just one equation in the book: E = mc 2
Albert Einstein.