Marie François Xavier Bichat

Marie François Xavier Bichat (14 November 1771 – 22 July 1802) was a French anatomist and physiologist who is best remembered as the father of modern histology and descriptive anatomy. Despite working without a microscope, he was the first to introduce the notion of tissues as distinct entities, and maintained that diseases attacked tissues rather than whole organs or the entire body, causing a revolution in anatomical pathology.