Zakī al-Arsūzī (in Arabic: زكي الأرسوزي; Latakia, June 1899 – Damascus, 2 July 1968) was a Syrian philosopher, philologist, sociologist, historian, and Arab nationalist. His ideas played a significant role in the development of Ba'athism and its political movement. He published several books during his lifetime, most notably The Genius of Arabic in its Tongue (1943).

Born into a middle-class family in Latakia, Syria, al-Arsuzi studied at the Sorbonne, where he became interested in nationalism. In 1930, he returned to Syria, where he became a member of the League of National Action (LNA) in 1933. In 1938, he moved to Damascus because of his disillusionment with party work, and in 1939, he left the LNA. In Damascus al-Arsuzi established and headed a group consisting of mostly secondary school pupils who would often discuss European history, nationalism and philosophy. Shortly after leaving the LNA, al-Arsuzi established the Arab National Party, an Arab nationalist party with a "defined creed". It was not a success and, on his return to Syria in November 1940 after a brief stay in Baghdad, al-Arsuzi established a new party, the Arab Ba'ath; by 1944, however, most of its members had left and joined Michel Aflaq's and Salah al-Din al-Bitar's Arab Ba'ath Movement, which subscribed to a nearly identical doctrine.

Ba'athism (Arabic: البعث‎ al-ba‘ath meaning "renaissance"/"resurrection") is an Arab nationalist ideology that promotes the development and creation of a unified Arab state through the leadership of a vanguard party over a progressive revolutionary government. The ideology is officially based on the theories of the Syrian intellectuals Zaki al-Arsuzi (according to the pro-Syrian Ba'ath movement), Michel Aflaq and Salah al-Din al-Bitar.

A Ba'athist society seeks enlightenment, renaissance of Arab culture, values and society. It supports the creation of one-party states, and rejects political pluralism in an unspecified length of time – the Ba'ath party theoretically uses an unspecified amount of time to develop an enlightened Arabic society. Ba'athism is based on principles of Arab nationalism, pan-Arabism, Arab socialism, as well as social progress. It is a secular ideology. A Ba'athist state supports socialist economics to a varying degree, and supports public ownership over the heights of the economy but opposes the confiscation of private property. Socialism in Ba'athist ideology does not mean state socialism or economic equality, but modernisation; Ba'athists believe that socialism is the only way to develop an Arab society which is truly free and united.

The Arab Socialist Ba'ath Party (also spelled Ba'th or Baath, "resurrection" or "renaissance"; Arabic: حزب البعث العربي الاشتراكي‎ Hizb Al-Ba'ath Al-'Arabi Al-Ishtiraki), also referred to as the pro-Iraqi Ba'ath movement, was a neo-Ba'athist political party headquartered in Baghdad, Iraq. It is one of two parties (with identical names) which emerged from the 1966 split of the original Ba'ath Party.

In 1966, the original Ba'ath Party was split in half; one half was led by the Damascus leadership of the Ba'ath Party which established a party in Syria, and the other half with its leadership in Baghdad. Both Ba'ath parties retained the same name and maintained parallel structures in the Arab world, but became so antagonistic that Syria — led by its Ba'ath party — became the only Arab state to support Iran against Iraq during the bloody Iran–Iraq War. Ba'athists seized power in Iraq for the first time in 1963, but were deposed several months later. The party's regional organisation governed Iraq between 1968 and 2003, for many years under the leadership of Saddam Hussein. The Arab Socialist Ba'ath Party – Iraq Region was banned in 2003 by the Coalition Provisional Authority following the invasion of Iraq.

The Arab Socialist Ba'ath Party (Arabic: حزب البعث العربي الاشتراكي‎ Ḥizb Al-Ba‘ath Al-‘Arabī Al-Ishtirākī) was a political party founded in Syria by Michel Aflaq, Salah al-Din al-Bitar and associates of Zaki al-Arsuzi. The party espoused Ba'athism (from Arabic: البعث‎ Al-Ba'ath or Ba'ath meaning "renaissance" or "resurrection"), which is an ideology mixing Arab nationalist, pan-Arabism, Arab socialist and anti-imperialist interests. Ba'athism calls for unification of the Arab world into a single state. Its motto, "Unity, Liberty, Socialism", refers to Arab unity, and freedom from non-Arab control and interference.

The party was founded by the merger of the Arab Ba'ath Movement, led by Aflaq and al-Bitar, and the Arab Ba'ath, led by al-Arsuzi, on 7 April 1947 as the Arab Ba'ath Party. The party quickly established branches in other Arab countries, although it would only hold power in Iraq and Syria. The Arab Ba'ath Party merged with the Arab Socialist Party, led by Akram al-Hawrani, in 1952 to form the Arab Socialist Ba'ath Party. The newly formed party was a relative success, and became the second-largest party in the Syrian parliament in the 1954 election. This, coupled with the increasing strength of the Syrian Communist Party, led to the establishment of the United Arab Republic (UAR), a union of Egypt and Syria. The union would prove unsuccessful, and a Syrian coup in 1961 dissolved the union.