The modern social world is unjust. It is also complex. What does this latter fact imply about the kind of approach that should be used in ameliorating the injustice expressed in the former fact? One answer, recently put forth by Jacob Barrett, is that _ideal theory_, which he understands as being fundamentally defined by the identification and subsequent pursuit of an aspirational macro-level institutional goal, lacks a place in social reform. The reason he thinks ideal theory lacks a place has (...) to do with its inability to deal with complexity. _Pace_ Barrett, I argue that ideal theory, suitably understood, can play a valuable role in social reform in a complex world. While some ideal theorists have underappreciated the extent to which complexity considerations complicate social reform, this does not mean that there is no place for it. This paper surveys the resources ideal theory has available to cope with what I call _the challenge of complexity_. Although the coping techniques will be successful to varying degrees, I believe, in aggregate, a compelling case can be made that ideal theory can combat the challenge of complexity. Still, one may worry that even if ideal theory can adequately deal with complexity, it cannot adequately deal with ever-changing social circumstances. Call this _the dancing landscape objection_. A static ideal theory cannot overcome it, but a _dynamic ideal theory_ could. In sum, dynamic ideal theory can contribute to social reform in a complex and mutable social world. (shrink)