Over the last few decades, aging research has emerged as a vibrant area of rigorous scientific study. With its humble beginnings in yeast and worms, the field has progressed so dramatically that scientists are now able to extend the lifespan of mice with the use of small molecule drugs. However, it was not too long ago that answering the more basic question, whether aging was amenable to scientific study, was itself a topic of contentious debate. To begin to understand how a field that was initially thought of as pseudoscience has come so far, it is instructive to understand its roots in both theory and practice.