複選題23 (AB) His work also generated interest in cognitive and developmental psychology. (AC) He continued to study the natural sciences and received his Ph.D. in Zoology from University of Neuchâtel in 1918. (AD) While this is a widely accepted notion today, it was considered revolutionary at the time. (AE) Epistemology is a branch of philosophy that is concerned with the origin, nature, extent and limits of human knowledge. (BC) It was Piaget's observations of his own children that served as the basis for many of his later theories. (BD) Today, Piaget is best known for his research on children's cognitive development.