In 1896 , Dr. Walter B. Cannon said , â The antivivisectionists are the second of the two types Theodore Roosevelt described when he said , â Common sense without conscience may lead to crime , but conscience without common sense may lead to folly , which is the handmaiden ( servant ) of crime . In 1896 , the physiologist and physician Dr. Walter B. Cannon said â The antivivisectionists are the second of the two types Theodore Roosevelt described when he said , â Common sense without conscience may lead to crime , but conscience without common sense may lead to folly , which is the handmaiden of crime .