Mathematics

## Lillian Pierce ’02 *09

### Mathematician, Marie Curie Postdoctoral Fellow, University of Oxford

I now have four degrees in mathematics—three of them from Princeton. My heart’s desire is to be a mathematics professor at a research university, sallying forth daily into the fantastically precise, pleasurable, mysterious (and yes, sometimes frustrating) world of abstract mathematics. It probably looks as though it would be hard to tread a more linear career path. But in fact my goals when I entered Princeton had nothing to do with a career in mathematics: I wanted to be a doctor. Meanwhile, because I couldn’t major in “medicine,” I figured I’d major in something I’d always loved and wanted to know more about: math. I thought it would be fun.

It was fun. It was also hard. Before arriving at Princeton, I happily had wielded the powerful tools of calculus without much thought about where they came from; at Princeton, the focus was on proving every single statement we used, from the most basic principles. At first, this is a shock for most students, as it was for me. But I quickly began to enjoy the discipline of proof for its own sake—the intricate, focused work reminded me of the way I practiced difficult technical passages as a serious violinist. I also got hooked on the precision and certitude that mathematics offered. There may be nothing quite as hard on the ego as having no idea how to solve a math problem, but on the other hand, there is nothing like the joy of insight when you finally figure it out. I always say to younger students, “Take math classes until they get so hard that you just can’t stand it. Then take one more.” This should get you through all four years!

Meanwhile, I loved all the other classes I took, too. Some days it was hard to decide what *not *to major in: chemistry, molecular biology, math, classics, psychology? The liberating thing about the Princeton liberal arts education was that I could take classes in all these fields, no matter my ultimate major. Moreover, each summer I explored one of my interests in depth within a research environment: a theoretical chemistry lab at Princeton (after freshman year), a cryptography program at the National Security Agency (NSA; after sophomore year), a molecular biology lab at the California Institute of Technology (after junior year), and back to the NSA (after senior year).

**Choosing between medicine and math**

But I still knew that I was going to be a doctor. In fact, by my junior year I had decided I wanted to complete not just an M.D. but an M.D./Ph.D., with a focus on computational biology, which I hoped would be a suitable blend of my disparate interests. But as my senior year approached, I had to acknowledge that while I loved working in a wet lab, and loved solving abstract math problems, I didn’t enjoy computational mathematics. I finally had to make a real decision: become a doctor (work in a lab), or do math (work in my head). At this point I had completed enough coursework that I was eligible either for medical school or math grad school, so it simply came down to figuring out what I truly wanted to do with my life.

Looking back, I realize that in some ways my persistent preparation for medical school was a protective fantasy: It allowed me to pursue something I really loved (math) but didn’t regard as a feasible career. Now, I know that math is one of the most utilitarian majors of all: The quantitative skills of a math major would be well appreciated in pretty much any discipline, from law, medicine, science, education, finance, politics, and technology to the arts. But at the time I entered college, pinning all my hopes on math, and a career in math, would have felt much too risky to me. I had always been “good at math,” but before coming to Princeton I had no special training in math, nor any reason to believe I was particularly special. Math *is *difficult, and mathematicians can sometimes seem like rare, semimythical creatures. But the remarkable education the math department provided gave me the confidence to think that I might just have what it took.

The undergraduate math program at Princeton is superlative. I took many classes (most with fewer than 15 students!) from extraordinarily famous mathematicians, learned intensively in office hours hosted by brilliant graduate students, and pursued individual research closely guided by professors. The rigorous coursework prepared me well for acceptance at one of the most demanding graduate programs, and stands me in good stead now as I begin to teach undergraduates myself. Even more importantly, I felt tremendously welcomed and nurtured by the department, and received unforgettable words of encouragement from a number of mentors. So when I had to make a decision about my career path, I decided to keep going with math.

Do I ever look back? I certainly have never regretted majoring in mathematics. No matter what career I chose, I would have been grateful for the ability to think with the algorithmic precision of a mathematician. On the other hand, I have never regretted all the courses I took outside of mathematics. I do have a deep fascination with biological problems, and I am grateful that the knowledge I gained as a pre-med student gives me at least a keyhole view into current research. In fact, I still can see medicine as a compelling alternative version of my life: pulling my utmost in the health/disease tug-of-war our society must constantly engage in. On the other hand, being a mathematician seems like, well, a once-in-a-lifetime opportunity. I suppose that’s the only risk of majoring in math: that you’ll fall in love with it and never want to stop.

*An asterisk (*) and number following a person’s name denotes that the individual earned a graduate degree from Princeton in that year.