The commencement of agriculture in the Holocene era is usually seen as heralding the beginning of a chain of events that eventually resulted in the Industrial Revolution and in modern economic development. The purpose of this paper is to outline and critically review theories about why and how agriculture first began. It also classifies these theories according to whether they are based on agriculture's development as a response to food deprivation, to a food surplus, or neither of these factors. Because agriculture began independently in several different geographical centres, it seems unlikely that the switch of early societies from hunting and gathering to agriculture was the result of the same cause in all of these locations. Moreover, the paper provides some new suggestions as to why hunters and gatherers were motivated to commence or increase their dependence on agriculture in some locations. Views about the role of natural resources and institutions in the development of agriculture are also discussed.