The Inspector's Role and Message
The Inspector acts as Priestley's mouthpiece - basically, he's the author's way of directly telling the audience what to think about capitalism. This is especially clear in his final, dramatic speech that warns of terrible consequences.
His most powerful quote - "If men will not learn that lesson, then they will be taught it in fire, blood and anguish" - is essentially a prophecy about war. Remember, this play was written after both World Wars, so audiences would understand exactly what "fire, blood and anguish" meant.
The religious language here makes the Inspector seem almost supernatural, like he's delivering divine judgment on capitalist society. Priestley is warning that if the wealthy don't start treating workers properly, society will collapse into violence and conflict.
Exam tip: The Inspector represents social responsibility - the idea that we're all connected and must look after each other, not just ourselves.