philosophical metaphysics, but ontologies are found in any scientific discipline. For example, in biology, an ontology might be comprised of a taxonomy of species and the ancestral tree that shows how they are related to one another. This ontology allows you to make inferences; if you know that a new species is in the mammalian part of the tree, you can infer that it will be warm-blooded. Increasingly, companies use machine learning programs to make such inferences, and to do so, they need to be supplied with an ontology. “We’re building an AI, and it needs to know about stuff. That’s what an ontology does,” Hart said. “An ontology is a web of concepts, a graph, which stores semantic content so that the AI might impersonate knowledge of the data structures”. For example, in his current role at Amazon, Hart might construct ontologies of different products (shoes, women’s shoes, soccer shoes) and how they are related.
Constructing an ontology of a domain requires knowing the parts it is made of and how they are all related. Learning the structure of many disparate domains is one of Hart’s favorite parts of the job. “I love building models of stuff, and I like learning about new areas. If you’re an ontologist and want to build a model of part of the world, you have to go become an expert in this kind of thing,” he said. “And when you do that, you have to be unafraid to say, ‘I don’t know what you’re talking about, I don’t know anything about this’. You have to do the Socratic gadfly thing, ‘is this what you mean?’”.
According to Hart, philosophers perform well as ontologists due to their openness to learning and to their ability to make conceptual distinctions. “One of the things I really like about philosophy of science that I get to do as an ontologist is say, 'scientists, you need some help. I'm not trying to help you qua scientist, I'm trying to help you qua philosopher. I’m going to take your knowledge, make some distinctions you didn't know were there. You'll get smarter as a result because you hadn't thought about disambiguated these things”. Frequent conceptual tools at Hart’s disposal are philosophical treatments of vagueness, the Duhem-Quine thesis, and the use-mention and analytic-synthetic distinctions.
While Hart found a great deal of continuity between philosophy and ontology as subject-matters, he was less confident about how to transition out of grad school into a non-academic job market. “My first job, Psycorp, hired a bunch of philosophy PhDs, so I fit in there and it had an academic vibe and allowed me to transition out,” he said.
Since then, Hart has gained perspective on how PhDs can market their experience in the private sector. “If you’re reflective about what you’re doing, you can do a lot,” he advised. “Think about the skills you have that would be beneficial in the private industry, about how you can take your grad school CV and adapt it into a resume. For example, dissertation writing is useful for saying that you are a self-starter and that you’re able to satisfy multiple stakeholders. Your teaching experience shows management, that you're able to oversee people's work. You have public speaking skills. All that kind of stuff is just incredibly useful.”
After years of living and working in Austin, Texas, Hart took a position for Amazon that allows him to work from home. Wanting to be closer to family back in the Pacific Northwest, Casey and his family - his wife, Nicole, and three daughters, Elizabeth (7), Juliette (5), and Anastasia (2) - sought out a home with good schools and room for their horses. “I drove down I-5 until it felt like I was out of the cities and had this existential, spiritual experience. I stopped in Roseburg, Oregon, got to a park, talked to a fisherman, and asked why would I want to live in Roseburg. He said, ‘there’s not much to do here, but it’s a great place for fishing, gardening, and raising a family’. So that’s where we stayed”.
When asked about his favorite memories of Madison, Hart said that he loved the feeling of Madison, that Madison taught him about biking, ultimate frisbee, and the value of a commute-free lifestyle. He recalled lots of interesting conversations with Peter Vranas and lots of interesting basketball games with Mike Titelbaum, who “can’t shoot a right-handed layup to save his life”.