Vatican II’s aggiornamento sought to reach out to the modern world with the message of the gospel in a way that was intelligible to the contemporary world. Fundamental theology was expected to play an important role in this process, but it has not been very successful in doing so. Set in this context, this article attempts to rethink the nature of fundamental theology. It uses a communication perspective to make a principled distinction between theology and fundamental theology, and goes on to clarify their tasks.