Keeping the doubt... Mary takes a look at how doubt and skepticism can be essential ingredients to faith. First, we hear from Rabbi Rami Shapiro - a rabbi who says he isn't religious. Instead, he describes himself as a curious, holy rascal in search of sacred cows to slaughter.

After that, a conversation with Michael Shermer, the founder of Skeptic Magazine. He tells Mary how he hammered Deepak Chopra (in his opinion) at a conference on consciousness and quantum physics. He also explains how, for him, the mind does not exist. The brain is just electric meat.