11.  For ethical reasons, experimental proof of direct person-to-person transmission is not feasible.

12.  Barker said that for ethical reasons, the team would prefer to do two transplants in a patient who has no use of either hand.

13.  A third is that for ethical reasons no patient could receive a placebo as a scientific control to allow more rigorous comparison.

14.  For ethical reasons, the human volunteers were not purposely injected with hanta virus, as the animals were.

15.  For ethical reasons, the children were still given the old treatment for ADA deficiency, consisting of regular injections of a synthetic form of the enzyme.

16.  For ethical reasons, researchers must continuously educate participants not to ease up on safer sex practices and other measures that can prevent infection without a vaccine.

17.  For ethical reasons, the newest drugs are tried first in patients with hopelessly advanced cancer.

18.  For ethical reasons, the Uganda study did not include a group of women and infants who received a placebo, or inert pill.

19.  However, consider the ethical reasons.

20.  Most, like Jean Thaler, do it for ethical reasons.