This is a recent title, published June this year. It is expensive at the moment, although with a fairly generous preview on Google Books. It argues that early Buddhist philosophy and meditation were intrinsically related and had a very different approach to that of the later Buddhist traditions.
The early Buddhist teachings were first of all verbalised reflections on meditative events. These reflections were then meant to guide meditative observations in order to cause future experiences to conform to these patterns of thought. Early Buddhist philosophy was thus first and foremost both a description and a prescription for meditative experience…Philosophy, as a form of direct perception that has been practiced to perfection, can be perceived in jhana