This article from the National Review is a good example of the more sophisticated arguments from groups opposed to embryonic stem cell research. The author cherry-picks medical successes using adult stem cells, fails to mention the many uncertainties and failures, and skips over noteworthy progress in embryonic stem cell work entirely. The fact of the matter is that regenerative medicine is a young field, and scientists still have a great deal to learn. We don't even know for sure how half of these therapies actually work! Any pronouncement on the efficacy of one branch of stem cell research over another is very premature - and usually ideologically motivated, as in this case.