Ecological Economics represents a line of thought relating to energy and the environment in economics, which can be traced back well into the 1800s. More generally, it places economics in the context of themes that have been central concerns for humanity since the ancient Greeks. In Barcelona in 1987, at a meeting hosted by Joan Martinez-Alier, the International Society for Ecological Economics (ISEE) was born, and the first issue of the journal Ecological Economics appeared in 1989. Studying the relationships between the economy and the environment is an optional extra for economists, and a minority pursuit. Addressing the economy as a price-making market system and unifying economics under deductive mathematical modelling has involved the conversion of all entities into objects. The incorporation of the Laws of Thermodynamics into economics in the early 1970s was key to the revitalised understanding of economics that became Ecological Economics.