I was asked this question by someone else and wondered if I could get better answers here: Is it fair to say that the standard model for matter is basically descriptive, without any underlying understanding of what causes its structure? Can it be compared it to the periodic table of elements BEFORE the discovery of the modern atomic model (nucleus plus electrons in shells) and quantum mechanics. Once one has the Schroedinger equation, plus spin, the periodic table becomes a trivial result, that can be derived in a few hours. But before one has the right fundamental equations, the chemical elements are just a mess of phenomena, some of which have some similarities. So are we are at the very point in physics where we were 100 years ago in chemistry? i.e.. we have the elements, we can put them in a table and we can even do "chemistry" with them, but what they really are eludes us. Eventually, we will find the correct equations. But is the standard model of high energy physics really it? Also take at the look at its full Lagrangian and tell me if you really expect this to be the fundamental equation of the universe? even without gravity!