Abraham Maslow's original 1943 paper introduced one of the most influential frameworks in psychology: the idea that human needs are arranged in a hierarchy, and that people are primarily motivated by the lowest unmet need in that hierarchy. At the base are physiological needs — food, water, sleep, shelter. Next is safety — security, stability, freedom from fear. Then love and belonging — friendship, intimacy, community. Then esteem — achievement, respect, recognition. Finally, self-actualisation — realising one's full potential. The key insight is not the names of the levels but the sequencing logic: a person who cannot meet their safety needs is not primarily motivated by belonging. A person without belonging is not primarily motivated by esteem. You cannot appeal to someone's aspiration while their survival is threatened. For any builder, leader, or communicator: understanding which level your audience is actually operating at is the prerequisite for reaching them effectively.