This paper elaborates the role and development of personal epistemologies when learning through and for work. It does this by drawing on explanatory propositions from psychology, sociology and philosophical accounts. The aim here is to go beyond conceptions of epistemological beliefs and to position personal epistemologies as being active, intentional, derived in personally particular ways through the unique set of socially derived experiences that comprise individuals' life histories or ontogenies. In this way, they are held to be comprehensive and encompassing as a conception to explain individuals' learning and as constructed through social experiences, albeit in person-specific ways. Given their active and constructive character, these epistemologies are placed centre stage in the dual processes of learning and remaking culturally derived practices, such as with paid work. These propositions are discussed and elaborated through a consideration of engagement and learning in forms of work that provide, respectively, relatively weak and rich forms of direct social guidance, and which require the enactment in different ways of individuals' personal epistemologies in the conduct of and learning through paid work.