Foucault's models of evolution

Foucault presents us with three models of “evolution” that preceded Darwin. Please explain in your own words Bonnet’s, Maurpertius’s and Robinet’s theory of succession/evolution.

Foucault discusses evolutionary thought after Classicism and before Darwin as a "...linking together of the table of identities and differences to the series of temporal events" (151). Foucault distinguishes this understanding of evolutionary thought from what science understands of it today, but also distinguishes the ideas of Bonnet, Maurpertius and Robinet from Classical knowledge about nature, which does not allow for a "...temporal series (to) be integrated into the gradation of beings", or a means of unifying the 'chart' to a 'series' of events (150).

Foucault discusses Bonnet's method of unification as one that understands evolution as a quest to a kind of perfection likened to God, from which we are so distant still, that we cannot yet even see if that gap could ever be bridged. Bonnet seems to model evolution as a linear and forward-moving series of species, such that as each type achieves the next stage of perfection, it actually becomes the next perfect species, so that a fish might become a bird, or an ape might become human, and something below an ape might become ape. The most perfect species then, in terms of complexity, will always be giving rise to a new species that is more like, yet infinitely distant, to God. Yet the distinction between different species will still be recognizable, since species do not blend, but progress into other species, which gives rise infinitely to multiplicity of beings. ("There will be Newtons among the monkeys and Vaubans among the beavers" 151-2). Foucault says that Bonnet's system supposes time as a factor of classification, and is used to generalize the unity of time to the unity of beings.

With Maupertuis, evolutionary thought conceives of time differently. Here, time is like a line of events that allows given variables (the charted characteristics of taxonomy) to emerge at certain times, but still insists of continuity in the 'fabric of beings'. In other words, exterior events (ruptures or changes in 'the conditions of the life of living beings) are what cause new species to come into existence. Yet, this model says that new forms are modifications defined through the memory of other living forms, until a chance 'deviation' gives rise to new species. Foucault says,"Maupertius supposes that the particles of matter are endowed with activity and memory" (154). Here the term 'memory' is used to tie together a succession of events into smaller units of continuity, while the term 'activity' allows for chance encounters and attractions to bring about more or less complex beings, as well as 'deviations' that add up to 'evolutions' into new species. Through these deviations, they array of variable characteristics is 'charted,' yet the conception of time as 'memory' of parent characteristics expresses continuity.

Similarly, Robinet's evolutionary notions suppose that 'continuity precedes time," meaning that all characteristics or variables of the 'chart' fall between an original simple model of complexities and the complexities that are evident in humans, and that history is a way to trace the possibilities of variables, rather than the continuous development of complexity or progress of a single 'living principle' that survives and changes according to the necessity of 'fitting-ness' to exterior conditions (Darwin). For Robinet and Maupertius, the 'fabric of beings' is seen as a way to let history fill out the chart of variable characteristics that are possible for nature. Robinet, however, sees the evolutionary trend as a 'project' toward the possibilities of complexity. This project is the feature that unifies the series of events in nature's history.