In this final chapter, the notion of philosophical complexity is revisited and further explored in terms of the prominent philosophical insights gleaned over the course of the study. It is argued that systemic openness is the defining feature that distinguishes complex systems from non-complex systems. As such, the concept of opening constitutes the theoretical frame through which the post-structural insights are interpreted and translated in this chapter. Opening gives rise to three paradoxes that define complex systems, namely that these systems are both ordered and disordered (and are constantly in a state of decay and renewal); complex systems are autonomous from, as well as dependent on, the environment; and, the identity of complex systems is both exclusive and inclusive. Each of these paradoxes is explored at the phenomenological level.