Wilhelm Friedrich Wolff
Marx dedicates his book to Wolff who is a close personal friend. Wolff was a German teacher, known for his days as a radical leftist student at university. As an adult, he was a notable communist who turned his attention from activism to influence when he became an editor in his later life.
Adam Smith
Marx is profoundly critical of Smith's economic theories. Since Smith's classical economics constituted the dominant mode of belief during that time, his reputation was a difficult one to question. This helped Marx gain popularity through controversy for his openly critical observations.
G. W. F. Hegel
He was a German idealist who became famous for his philosophy. He became known for establishing the concept of absolute idealism in the field of philosophy. His ideas integrated aspects of sociology with the mind/spirit, and human history. He was primarily concerned with establishing a method by which people could escape the dualist perspective by making two opposing concepts work in harmony with one another. Marx draws heavily upon Hegel's philosophical ideas in order to establish his arguments about human nature as it relates to economy.