Crossing the River

The farmer wants to get his goat, wolf and cabbage to the other side of the river. His boat isn't very big and it can only carry him and either his goat, his wolf or his cabbage. Now.....if he leaves the goat alone with the cabbage, the goat will gobble up the cabbage. If he leaves the wolf alone with the goat, the wolf will gobble up the goat. When the farmer is present, the goat and cabbage are safe from being gobbled up by their predators.