Baron de Montesquieu's brand of functional analysis is radically different from that offered by Auguste Comte and Herbert Spencer, both of whom tried to find what all social systems must do to maintain themselves. Montesquieu distinguishes three types of government: republican, monarchical, and despotic. Sociologists and anthropologists have largely neglected this typology in the belief that it is essentially a restatement of classical political thought dating back to Aristotle. A salutary aspect of Spencer's theory is its attention to the way in which types of social organization cycle in and out rather than simply following a unidirectional path of change. Spencer's cycles are not mechanical, alternating between ways of life at regular predestined intervals. Rather, the process of cyclical change is driven by environmental changes. Crawford S. Holling argues that the increasing strength of connectance between variables in the maturing ecosystem eventually leads to an abrupt change.