Every man is duty-bound not only to his parents, family members, society, country, humanity, other living beings, the demigods, etc., but also to the great philosophers, poets, scientists, etc: Revision history
Diff selection: Mark the radio buttons of the revisions to compare and hit enter or the button at the bottom.
Legend: (cur) = difference with latest revision, (prev) = difference with preceding revision, m = minor edit.