The Old Testament teaches that the [[life]] of all flesh is its [[blood]] ({{Bible ref|book=Leviticus|chap=17|verses=13-14|version=KJV}}). Secular science remained ignorant of the properties and circulation of blood until the 17th century A.D. | The Old Testament teaches that the [[life]] of all flesh is its [[blood]] ({{Bible ref|book=Leviticus|chap=17|verses=13-14|version=KJV}}). Secular science remained ignorant of the properties and circulation of blood until the 17th century A.D. |