In his Muqaddimah (1377), he wrote that black skin was due to the hot climate of sub-Saharan Africa and not due to African lineage.
Oma raamatus Muqaddimah (1377) selgitab ta, et musta naha põhjustajaks on Lõuna-Sahara piirkonna kuum kliima, mitte sealsete inimeste päritolu.