Hendrick Peter Godfried Quack (2 July 1834 – 6 January 1917[1]) was a Dutch legal scholar, economist and historian, who is best known for his work De socialisten: Personen en stelsels ("The socialists: persons and systems").

In Amsterdam, he attended lectures by Jeronimo de Bosch Kemper and Martinus des Amorie van der Hoeven, both Christian critics of liberalism.

Having been appointed professor of political economy at Utrecht University in 1868, Quack presented his students with socialist theories of economics besides teaching the common curriculum of the time.

He proceeded with his historical work, and in fact one of the reasons for switching jobs was the increase in salary, which he needed to buy more books for his studies.

[4] Quack was to join the board of directors of De Nederlandsche Bank in 1885, also becoming professor extraordinaire[a] of the history of political economy at the University of Amsterdam, which he remained until 1894.