Theo makes all knowledge open for inspection. Access to any bit of knowledge in Theo is all mediated in the same way. If the knowledge already exists it is obtained from the value of the corresponding slot. If the desired knowledge is not present, an impasse is automatically generated, and Theo makes it its duty to figure out the value of the slot. If successful, the value of the slot is then returned, as was the case for the pre-existing knowledge.
Having global representation and uniform access to knowledge greatly aids Theo's meta-knowledge. This is turn aids meta-reasoning.
Related principles that aids meta-reasoning are that all knowledge is globally accessible (glassbox knowledge) and uniformly represented using a frame-based knowledge representation system.
Go to a discussion of this property for multiple architectures.