The idea of intensification was put forward by a number of archaeologists, but the most prominent in developing the idea was Harry Lourandos. Intensification is an idea that posits that change in economic systems of peoples is controlled by social changes. This means that change can occur without an external force such as environmental change. The idea is derived from a 1990s debate about the Tasmanian Aboriginal people and whether large social/economic change was caused by environmental factors (see "Environmental determinism"), or from factors within the society. The predominant view at the time held that in the case of the Australian Aboriginal and Torres Strait Islander people any social change was largely influenced by external, largely environmental, factors.