In short, innocence and wisdom are explored through the character of Bruno in The Boy in the Striped Pajamas. Bruno's innocence often proves his wisdom. Bruno is innocent of the philosophical evils and the physical evils behind the Nazi regime. Due to this innocence, Bruno questions everything. It is in this questioning that Bruno exerts his wisdom and finds the truth. Here is a quotation that is a perfect example:
What exactly was the difference? He wondered to himself. And who decided which people wore the striped pajamas and which people wore the uniforms?
Bruno shows his innocence here in his confusion. He cannot understand why the Nazi soldiers have placed certain people inside the fence while others remain outside. The wisdom Bruno imparts here is apparent: there is not a difference between the two kinds of people (Germans and Jews). They are all humans and, as such, are worthy of respect.