Allan Kardec was a French educator and philosopher, best known for founding the spiritualist movement known as Spiritism. Born on October 3, 1804, he published several influential works, including "The Spirits' Book," which outlines the principles of Spiritism and the nature of spirits and their interactions with humans. Kardec's approach combined scientific inquiry with philosophical exploration, aiming to understand the moral and ethical implications of spiritual phenomena. His teachings emphasized the importance of personal development and the pursuit of knowledge, influencing many spiritual and philosophical movements worldwide.