Answer:
Enduring hard times strengthens character.
Step-by-step explanation:
The theme that can be found in both "If" and The Jungle Book by Rudyard Kipling is that enduring hard times strengthens character.
This is because, in IF and Jungle Book, there are circumstances that come up against the protagonists and other minor characters that sees hard times test their character and they finally triumphing and having their character strengthened.