Jonas Salk: I didn’t doubt it. I just questioned the logic of it, the reasonableness of it, when other people accepted it. I just didn’t accept what appeared to me to be a dogmatic assertion in view of the fact that there was a reason to think otherwise. So that it was not merely doubting a belief, there was a principle involved. I try to understand the laws of nature, the principles that are involved, and that’s what I’ve attempted to do ever since then, in the development of what I think of as the science of vaccinology, which had not been a science prior thereto. I entered medicine with the idea of bringing science into medicine. I had the opportunity to investigate this question scientifically, thinking and working as a scientist.

I was not trained as a scientist. I was trained in medicine. And, so my functioning, you might say, as a medical scientist, came through being self-taught through the experience of investigating the questions that were of interest to me.  And, I had no formal training as a virologist, or as an immunologist.  But, I learned what I needed to know in order to address those questions.