Revisiting the Warnock rule

Spurred by recent announcements that researchers in the UK and USA had sustained human embryos in culture for nearly two weeks, Nature Biotechnology collected commentaries from more than a dozen experts on whether it was time to reassess the 14-day rule. Much of the discussion focuses on the potential benefits of studying the “black box period” of human embryonic development, between about 7 days and 28 days, and on questions of who should decide whether the two-week limit might be breached in the interest of learning more about this period. In his comments, Observatory Co-Director Ben Hurlbut emphasizes that the scientific community’s embrace of 14-day rule signaled both an acknowledgement on the part of researchers of the need to set ethical limits and a signal that they were willing to defer to broader society’s judgments about the value and acceptability of proposed research. As a result, calling the rule into question on the basis of “internal scientific and ethical judgment” (2017:1032) endangers the relationship between science and democracy.