Argumentation in Theory and Practice: Gap or Equilibrium?

It is not uncommon, in argumentation and in various professions, to diagnose a gap between theory and practice; and in the next step argue that they should be brought into line with each other. But what does this mean? I shall argue that some version of a gap is sound, as it leaves theory with a critical, independent role in relation to practice – something that an equilibrium view does not.