Response to Professor Eugene Rosa's viewpoint to our paper

This note provides a response to Professor Eugene Rosa's viewpoint to our paper On Risk Defined as an Event Where the Outcome is Uncertain published in this journal in January 2009. We argue that his summary of our work does not reflect what we are saying in the original paper. We restate that Rosa's definition represents one possible way of looking at risk, but there are others, including ours. Rosa's definition separates ontology and epistemology, which is an attractive property, but it leads to some conceptual difficulties which our definition avoids.