This book constitutes the proceedings of the Second International Conference on Human and Artificial Rationalities, HAR 2023, which took place in Paris, France, in September 2023. 

The 18 full and 5 short papers included in this book were carefully reviewed and selected from 39 submissions. They were organized in topical sections as follows: Human and artificial thinking; human thinking and reasoning; neuropsychology and interaction; artificial agents and interaction; and applied reasoning. This volume also contains 2 invited talks in full-paper length.    Chapter 21 is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.