The Holy Family: Critique of Critical Critique is the first joint work of Karl Marx and Friedrich Engels. At the end of August 1844 Marx and Engels met in Paris and their meeting was the beginning of their joint creative work in all fields of theoretical and practical revolutionary activity. By this time Marx and Engels had completed the transition from idealism to materialism and from revolutionary democratism to communism. The polemic The Holy Family was written in Paris in autumn 1844. It reflects the progress in the formation of Marx and Engels' revolutionary materialistic world outlook.