"Minnebreeven; On Free Labor in the Netherlands Indies; Impressions of the Day" is a collection of letters by Multatula, a Dutch writer and journalist, reflecting his thoughts on social problems and injustices that existed in colonial Indonesia. In his letters, the author reveals the life and suffering of the local population, expresses his criticism of the colonial policy of the Netherlands, and also suggests ways to solve these problems. This book is an important document about the history and social aspects of the colonial era and challenges the reader to think about morality and justice.