The quote "I think, therefore I am," originates from the French philosopher René Descartes. In Latin, it is phrased as "Cogito, ergo sum." This statement is foundational to Descartes’ philosophy, emphasizing the importance of doubt and questioning as a pathway to knowledge. He used this concept to conclude that while he could doubt the existence of the external world, the very act of thinking proved his own existence. Descartes is often regarded as the father of modern philosophy, and his work laid the groundwork for subsequent philosophical thought, influencing a wide array of disciplines, including psychology and cognitive science.