arXiv1999
This conference shows the impressive rate of advances in the observations and theoretical interpretations of large-scale structure. But to explain my feeling that we may still have a lot to learn I offer some comments on our sociology, informed by social construction, in adopting lines of thought that tend not to follow straightforward readings of what is observed. Thus galaxies are thought to be affected by environment, not only in the morphology-density relation, but also as the cause of biased formation. But the Tully-Fisher and fundamental plane relations do not allow much room for the contingencies of environment. It is thought that the galaxy distribution is not likely to be closely related to the mass, yet most dynamical analyses indicate that if the mean density is low then optically selected galaxies are good mass tracers. The evidence is that at redshift unity the larger spiral and elliptical galaxies were by and large in place, as were a good fraction of the great clusters of galaxies. These galaxies evolve slowly at $z<1$, yet we hears of rapid evolution not much before this, in galaxy formation. Perhaps all these examples are misleading. But, as Kuhn has taught us, complex interpretations of simple phenomena have been known to be precursors of paradigm shifts.