This article examines current understandings regarding the causes of child maltreatment and its prediction and prevention. The answers to why some people hurt children, when others in similar circumstances do not, remain obstinately elusive. We look to philosophy to help understand the complexity of causal pathways of maltreatment. We draw on the seminal work of Mackie. on probabilistic causation and his notion of the 'INUS condition' (INUS is the acronym for insufficient but non-redundant part of a condition that is itself unnecessary but sufficient for the result). This theory holds particular relevance for exploring complex social phenomena. Taking child abuse as an issue, we show how the concept of the INUS condition offers a new way of thinking about causal factors when they are neither necessary nor sufficient. It can be applied to clarify the complex nexus of potential risk factors that may - or may not - 'cause' adult perpetration of abuse. It also provides a framework for integrating the research on resilience factors with that on risk. Finally, we discuss the lessons for research, policy and practice that arise from this way of conceptualising the underlying causality of child maltreatment.