Preachers and scholars who have been described as revivalists (Mujaddids) or "mujaddideen", by differing sects and groups, in the history of Islam include Ahmad ibn Hanbal, Ibn Taymiyyah, Shah Waliullah, Ahmad Sirhindi, Muhammad ibn Abd-al-Wahhab, and Muhammad Ahmad. In the 20th century, figures such as Hassan al-Banna, Abul Ala Maududi, Malcolm X, and Ruhollah Khomeini, have been described as such, and academics often use the terms "Islamist" and "Islamic revivalist" interchangeably. Contemporary revivalist currents include Islamic liberalism, which seeks to reconcile Islamic beliefs with modern values; neo-Sufism, which cultivates Muslim spirituality; and neo-fundamentalism, which stresses obedience to Islamic law and ritual observance.