Ernest Renan was a French philosopher, historian, and writer born on February 28, 1823. He is best known for his works on the history of early Christianity and his influential essay, "What is a Nation?" In this essay, Renan explored the concept of national identity and the importance of shared experiences and memories in forming a nation. Renan's ideas contributed significantly to the fields of philosophy and sociology, particularly in understanding nationalism. He also wrote extensively on religion, emphasizing the need for a rational approach to faith. Renan passed away on October 2, 1892, leaving a lasting impact on modern thought.