This chapter proposes an account of learning at and for work comprising the collective contributions of social and brute mediating factors and individuals' processes of mediating those contributions. That is, an account of individuals' learning and development accommodating both the inter- and intra-psychological contributions and the relations between them. It also seeks to redress the concern that in recent times, the mediation of individuals' knowledge has become overly associated with proximal social influences on human cognition as well as those of signs, symbols and artefacts within Vygotskian-inspired social constructivism. Seemingly overlooked in this privileging are: firstly, the contributions of brute facts (i.e. nature) both within and beyond individuals, and, secondly, how individuals themselves mediate the suggestions of social and brute factors (i.e. inter-psychological processes). Together, these mediating factors comprise the suggestions of the social and natural worlds can sometimes, but not always (e.g. maturation), be negotiated with. Then, there are the ways that individuals exercise their engagement with these suggestions and come to construe and construct what they know and do (i.e. personal mediations). Together, these factors prompt a more inclusive account for how intra-psychological or intra-mental contributions and processes mediate learning at and through work. Certainly, understanding processes of mediation more fully requires a consideration of both inter-psychological and intra-psychological processes, and how their contributions are brought together in advancing workers' learning and development