In org.drools.runtime.conf, there's a class with the unlikely name:
BeliefSystemTypeOption
Well, you gotta have faith, and I'm sure that one day there'll be a
revelation and tell us all about this option.
Meanwhile, we can amuse ourselves by reading the source code, where
the "belief" is frequently replaced by "belie". Since method
getBelieSystemType() is documented as "Returns the configured clock
type", it's probably not too far off.
-W