First of all: I didn't watch the enitre debate, I just saw the video the 2+2=5 scene in a shortcut. I don't unterstand the point of Krauss. What was he trying to show us with his t-shirt 2+2=5?If he wants to disrespect logic and philosophy, it backfires against himself because science itself is based on logic. It ended up in a laughing crowd and Krauss embarassing himself.
He is saying that William Lane Craig’s arguments of are not true by necessity no matter how “logical” they seem. Krauss is implying that his math/physics based arguments hold up because they withstand the scrutiny of analysis, not because they sound good. He is saying that’s all that counts, not our beliefs.