Jean Piaget

Original Constructivist. Jean William Fritz Piaget (UK: /piˈæʒeɪ/,[17][18] US: /ˌpiːəˈʒeɪ, pjɑːˈʒeɪ/,[17][19][20][21][22] French: [ʒɑ̃ pjaʒɛ]; 9 August 1896 – 16 September 1980) was a Swiss psychologist known for his work on child development. Piaget's theory of cognitive development and epistemological view are together called "genetic epistemology". https://en.wikipedia.org/wiki/Jean_Piaget