Li briefly outlines three generations of intelligence research over the past 100 years with attention to the origins and limitations of early investigations and the resulting confusion and disagreement in modern reinterpretations of the findings. He discerns an emerging consensus among scholars and researchers that intelligence should be considered primarily as a product of thinking and learning. To find the essence of how thinking is possible and what learning is, Li investigates theory and research in cognitive psychology, developmental linguistics, animal behavior, and many other related disciplines. He proposes the notion of conceptual intelligence, i.e., human intelligence, as a result of thinking and learning through concepts. Li traces how the human species created concepts, and how conceptual thinking and conceptual learning make the human species intelligent and creative. There is nothing mysterious, intuitive, or innate about it. Our past thinking and learning has created the intelligence of today and will continue to create our intelligence in the future. How to think deeper and learn better are the difficult questions for us now as we consciously venture into new arenas of problem-solving and cognition.