This chapter will motivate why it is useful to consider the topic of derivations
and filtering in more detail. We will argue against the popular belief that
the minimalist program and optimality theory are incompatible theories in that the
former places the explanatory burden on the generative device (the computational
system) whereas the latter places it on the fi ltering device (the OT evaluator).
Although this belief may be correct in as far as it describes existing tendencies,
we will argue that minimalist and optimality theoretic approaches normally adopt
more or less the same global architecture of grammar: both assume that a generator
defines a set S of potentially well-formed expressions that can be generated on the
basis of a given input and that there is an evaluator that selects the expressions from
S that are actually grammatical in a given language L. For this reason, we believe
that it has a high priority to investigate the role of the two components in more detail
in the hope that this will provide a better understanding of the differences and similarities
between the two approaches. We will conclude this introduction with a brief
review of the studies collected in this book.