Does it work? A scholastic epistemology perspective on evidence-based practice in social welfare

Contemporary "knowledge" relies increasingly on probabilistic data. A key example is the "evidence" for the effectiveness of health and social welfare interventions. Such claims to "knowing" require an epistemological underpinning. This paper explores the concept of probabilistic knowledge, evidence and "proof" which underpin claims for the effectiveness of social welfare interventions from the perspective of scholastic epistemology. It provides a framework based on contingent events, establishing different levels of certitude and ways of increasing it, thanks to intellectual virtues such as prudence and art. Knowing the value of the data that form the basis for making decisions in social processes, we can construct directions for social policies. Greater methodological precision (that philosophy in its various traditions might offer) may be of service to attempts in social work to conceptualize questions of effectiveness and measurement of outcomes, given their probabilistic nature.