Why in the world is the notation [tex]\left(\frac{\partial T}{\partial V}\right)_S[/tex] so ubiquitous in thermodynamics when it means exactly the same thing as [tex]\left(\frac{\partial T}{\partial V}\right)[/tex], that is, the partial of T with respect to V. The definition of a partial is that all the other variables are held constant! Is the problem just that physicists need a constant reminder of what a partial derivative is or what!?!