A number of developments brought the field of childbirth and birth defects into the medical field. The introduction of scientific thinking by Francis Bacon encouraged systematic and evidence-based theories.  Studying abnormal bodies became a method for understanding normal functions.  In addition, dissection became more acceptable, allowing physicians to examine intricate details.41  Prior to this, doctors even had to guess if conjoined twins had one heart or two.  The greater role of science did not occur quickly or offer a panacea to all cases of deformities.  However, it was an important movement that slowly disproved many popular ideas.