Explicit rules are necessary in plastic domains
To perform well in changing situations, or plastic domains, cognitive systems need access to explicit rules they can manipulate and redescribe. Connectionist networks lack explicit representations of the law needed to perform such a redescription.
At best, the network can be subjected to extensive retraining.
Andy Clark, 1992.
Note: In making this claim Clark draws on the developmental psychology of Annette Karmiloff-Smith.