Essentialism is an educational theory that advocates teaching students a core set of common knowledge and skills in a systematic way. It began in the US in 1938 and focuses on building basic concepts through disciplines like literature, math, science and history. Essentialism is teacher-centered and believes the teacher's role is to impart essential knowledge and skills to help students become productive citizens. It emphasizes mastery of content through strategies like lecture, homework and memorization. While it ensures students receive a strong basic education, it is criticized for lacking focus on individual learning styles and creativity.