This volume focuses on the role of the postulated derivational and filtering devices in current linguistic theory and aims to promote the exchange of ideas between the proponents of MP and OT in order to evaluate the role of these devices in the two frameworks. It sheds more light on the tenability of the often proclaimed opinion that MP and OT are incompatible frameworks given that the explanatory power of the former mainly resides on the generative device whereas the explanatory power of the latter mainly resides in the filtering device. Papers from various perspectives discuss and compare the two devices in the two frameworks. The volume thus collects a large number of the arguments in favour of more a strictly derivational approach, a more strictly filtering approach, or a more hybrid approach. The book will be of interest to any researcher or advanced student in Linguistic Theory. It is more specifically directed to syntacticians working within the current frameworks that have developed from Chomsky’s minimalist program (MP) and Prince and Smolensky’s Optimality Theory (OT).