Answer:
The theme in The Oilman and His Sons:
There was quality in solidarity and that family should help one another. When the log was entire, it was troublesome for them to break however once it was separated into littler pieces, it broke easily.
When they each had a lot of their legacy, they fell into poverty. The dad told his children that they ought to help each other. When one individual in the family is in need, the others must help.