The document summarizes several adult learning and development theories. It discusses Knowles' principles of andragogy, which focus on adults' internal motivation and relevance of learning. Four major theories are outlined: Perry's model of intellectual development involving dualism to relativism; Belenky's model of women's ways of knowing from silence to constructed knowledge; Kitchener and King's model of reflective judgment from pre-reflective to reflective thinking; and Baxter-Magolda's model of epistemological reflection among college students from absolute to contextual knowing. The implications of these stage-based theories involve a shift from external to internal definitions of knowledge with meaning constructed through experience.