Originally, thumos is a Greek word expressing the concept of “spiritedness”. The word indicates a physical association with breath or blood and is also used to express the human desire for recognition. More at Wikipedia
Thumos was first chosen by Mike Vanseveren (in tank top) in 2015 as the name of a three-member group as Thumos 3, also known as T3Group, whose purpose is to write the first book of thumos. In the following picture, from left to right, Nickantony Quach, Mike, and Mark Canny were on a ferry from Providence to Newport, Rhode Island, on Independence Day to celebrate the release of their first book, THUMOS Adulhood, Love & Collaboration, which is written by Mark Canny and Nickantony Quach.
As shown in the following picture, their celebration ended with a nice meal in Wayland Square, where the group was formed.