We hope that the preceding presentation has made it clear that the glass transition is not a simple phenomenon, but a very complicated process which is still not understood in all of its ramifications. The nature of the glass transition temperature (Tg), to begin with, has been the source cf considerable controversy for many years. The observation of its rate effects, on the other hand, and its similarity to second-order transition, on the other, has caused much confusion. It is not until recently that there is promise for reconciliation. It appears at present that Tg is what one experimentally observes when the material is on its “slow boat” to T2 In other words, Tg is a kinetic manifestation of a thermodynamic process (T2). There is, in fact, no inherent controversy between these two views, since each explains one aspect of the “many-faced” transition. The solution of this problem was actually alluded to in the classical paper of Kauzmann, although it was not recognized as such. The credit of explicit clarification goes to Gibbs and DiMarzio, who first argued the case in quantitative terms.