The discussion revolves around the definition and properties of the stress tensor, emphasizing its symmetric nature and its role in relating surface forces to internal stresses within a medium. Participants explore the implications of arbitrary additions to the stress tensor and their compatibility with established equations of state, such as the Navier-Stokes equation and the ideal gas law. The conversation highlights the divergence of the stress tensor and its significance in converting surface integrals to volume integrals, reinforcing the need for a clear understanding of its mathematical representation. Additionally, there is a debate about the notation used for stress tensors and the integration of differential forms in expressing physical laws. Overall, the thread reflects a deep engagement with the theoretical underpinnings of the stress tensor in both classical and relativistic physics.