This volume includes twenty-three original essays written by friends and former students of Mauro Mariani and Carlo Marletti. In 2019 both Carlo and Mauro are turning 70 and this Festschrift is our way to celebrate and honour them. After the philosophical profiles of Mauro and Carlo, the essays, arranged in alphabetical order, tackle issues pertaining to (history of) logic, metaphysics, philosophy of language and linguistics. Some contributors do not shy away from mathematical technicalities, others pay attention to the classical sources of contemporary philosophical ideas. All papers focus on Carlo’s and Mauro’s favourite research topics.