Course 1 first explores the basics of both macroscopic and microscopic thermodynamics from a postulatory point of view. In this view, the meaning of temperature, thermodynamic pressure and chemical potential are especially clear and easy to understand. In addition , the development of the Fundamental Relation and its various transformations leads to a clear path to property relations and to the concept of ensembles needed to understand the relationship between atomic and molecular structural properties and macroscopic properties. We then explore the relationship between atomic and molecular structure and macroscopic properties by taking a statistical point of view. Using a postulatory approach, the method for doing this is made clear. This leads to the development of the partition function which describes the distribution of molecular quantum states as a function of the independent, macroscopic thermodynamic properties.