What is interdisciplinarity? What to make of it? What forms does it take? What drives it? The remarks to follow seek to offer a relatively broad overview of selected key concepts and key issues that together help identify and assess the very complex and non-unitary phenomenon of interdisciplinarity. In the literature on interdiscplinarity, there has been a pressing need for more systematic and elaborate accounts. Even if very sketchy, what follows is an attempt to take a step or two towards that direction. Rather than anything final and complete and detailed, I submit a programmatic outline that requires follow-up investigations by way of further conceptual clarifications and empirical case studies.