The moral of these stories is that a node cannot necessarily trust its own judgment of a situation. A distributed system cannot exclusively rely on a single node, because a node may fail at any time, potentially leaving the system stuck and unable to recover. Instead, many distributed algorithms rely on a quorum, that is, voting among the nodes (see “Quorums for reading and writing”): decisions require some minimum number of votes from several nodes in order to reduce the dependence on any one particular node.
