Analyzing causality in safety science

We’re happy to announce that Brian Hanley successfully defended his doctoral thesis “A Pragmatic Epistemology of Causal Selection in Safety Science” on April 14, 2021. His defence committee included Dr. Ken Waters (supervisor), Dr. Marc Ereshefsky, Dr. Megan Delehanty, as well as internal examiner Dr. Nicholas Turner (Haskayne School of Business) and external examiner Dr. James Woodward (University of Pittsburgh).

We asked Brian to share more about his thesis topic, as well as his graduate studies experience.

1. Can you summarize your thesis topic, specifically for those of us who don’t have a background in philosophy?

Disasters in sociotechnical systems are caused by many factors. For example, the tragic chemical disaster in Bhopal, India, was caused by a leaky valve and a maintenance error. Safety scientists and investigators call these proximate factors. But the tragedy was also caused by what experts call systemic factors, which include the facility’s design, the organization of its workforce, and the safety culture of the plant and surrounding community. Other disasters share a similarly complex causality, depending on a multitude of proximate and systemic factors. Investigators and scientists distinguish between these different types of factors because they think each has distinctive causal features and also because they often think some factors are more significant causes of disasters than others.

In this dissertation, I analyze these distinctions and the reasoning experts use when selecting important causes of disasters in cases like the Bhopal gas tragedy and the Challenger shuttle loss. Using James Woodward’s interventionist theory of causation, I explicate three causal concepts that can be used to distinguish among causal factors: amplifying/damping, causal inertia, and causal delay. I employ these concepts to elaborate and clarify the causal features safety scientists identify to draw distinctions among different types of causal factors, and their reasons for thinking some causes are more important than others for understanding disasters.

2. How did you decide on this topic and the supervisor you worked with?

I began working with Dr. Ken Waters in my second year in the graduate program. I had taken a course where the class read and discussed some of his work on causal reasoning in biology. There I learned about James Woodward's work and the philosophical questions about causation that would frame my dissertation. That summer, I became fascinated by why scientists selected some causes of outcomes as more important or more useful than others. I began looking to develop conceptual tools and a method of analysis that could help understand how this selective reasoning worked and why knowledge of some types of causes is more useful than knowledge of other causes.

3. What was the most valuable outcome (and/or best experience) of the graduate program for you?

A lot has happened in my several years in Calgary, and all of these experiences are valuable in their own ways. What stands out most, though, are the times during a year of great tragedy that could have easily derailed my time in philosophy, where my friends and mentors in the program went out of their way to care for me, and help me through it. I will always value those efforts, that kindness, and their friendship. I also once made tacos for all the grad students…that was pretty great, too.