You know he is a medical doctor right? He actually does understand science. I don't agree with him on everything, but he wouldn't be an MD if he didn't understand biology.

I think the key thing about Deepak Chopra is that he doesn't take western medicine or western science as the only paths to truth or healing. And for a lot of people who see the only valid forms of medicine or understanding of the world as those that follow specific western medical standards or western scientific models, it's seen as pseudoscience.

However from what I've read of his work, he's usually talking from a mystic perspective rather than a scientific perspective.