If there is one thing Legion knows for certain, it is that everyone is selfish. That is unless they are stupid. So he doesn't believe that the god of steam is the savior of mankind.
But he didn't make his doubts known to the high priest. He just listened to the man brag about the Church of Steam for a while.
Then the high priest got to the point, "I see that you are talented with machines. It has to be that, or the god of steam wouldn't have paid attention to your patent so quickly."
"I advise you to take advantage of this talent by becoming a machinist. If you do, you might invent something that will help you ascend the ranks as soon as possible."
Legion knew that this was the main reason why the high priest was bragging about his church. He also suspects that it was the god of steam that put him up to this.
So he didn't tell the high priest to shut up and mind his business. Instead, he became solemn and quiet as if he was considering the proposition.
