The Leibnizian structure we discovered in Difference and Repetition and Logic of Sense returns in The Fold. Although its central elements remain the same, there are some key differences. Here, for the first time, Deleuze is careful to introduce each element of his reading of Leibniz in a particular order. In the lecture series on Leibniz that Deleuze gave in 1986, at around the same time The Fold was written, Deleuze calls this a ‘non-philosophical reading’ of a philosopher, and insists it must accompany any philosophical understanding of Leibniz. This non-philosophical reading relies on a kind of intuitive deduction of the impetus behind Leibniz's creation of certain concepts: ‘all sorts of sensible intuitions that you must allow to be born within you; extremely rudimentary sensible intuitions, but by the same token, extremely lively’ (16/12/1986). Thus, for example, we will see that when Deleuze initially asks ‘why are things folded?’, the intuitive answer he relies on to advance his account is ‘in order to be put inside something’. It is only on this basis that we move from the folded nature of predicates or events to their ‘inclusion’ in subjects or individual notions. Regardless of how we interpret the legitimacy of this method, it at least demonstrates the extent to which The Fold presents Leibniz's philosophy, for the first time, as a unified whole, all of whose elements are connected.

The Fold starts with a discussion of curvature in Leibniz's conception of matter. Deleuze draws on Wölfflin's analysis of Renaissance and Baroque architecture to characterise the propensity for curved forms with fuzzy edges and the neglect of sharp edges – a propensity that finds its correlate both in the contemporary mathematical problem of curved lines and figures and in Leibniz's own philosophical conception of infinitely divisible matter. We discover, however, that Leibniz's infinitely divisible, continuous matter ends up referring to centres of unity that exist outside of the material domain. Deleuze's non-philosophical progression thus moves us to a different domain, where metaphysical unities or souls exist. It is here that Deleuze's Leibnizian structure returns in familiar form. Once again, Deleuze describes a process through which singular points (this time themselves understood as points of inflection or folds) are enveloped by monads that come to occupy certain points of view.