Existing computational approaches to cognition generally adopt a static strategy. Conversely, it is argued that broadening the notion of software reliability for cognitive architectures ultimately leads us to acknowledging the diachronic nature of cognition. In turn, this observation suggests a new set of requirements fora cognitive architecture, including strong tractability and avoidance of epistemological commitments. These requirements can be satisfied by a time-constrained model of memory, which takes the form of a massively parallel network of objects exchanging simple signals. All knowledge is expressed in a separate knowledge base organized into an object-oriented hierarchy.