Kohlberg's stages of moral development were influenced by Piaget's stages of cognitive development. Kohlberg identified 6 stages of moral reasoning grouped into 3 levels - pre-conventional, conventional, and post-conventional. In the pre-conventional level, morality is based on consequences. In the conventional level, morality is based on social norms. In the post-conventional level, morality is based on principles of justice. Kohlberg believed that individuals progress through these stages in a fixed order as their moral reasoning becomes more advanced.