Florian Vermeiren, a postdoctoral researcher at KU Leuven’s Institute of Philosophy, presented an in-depth analysis of Spinoza’s metaphysics. The presentation took place at the conference “Spinoza and Negativity” at KU Leuven, Belgium, on September 25–27, 2024. Vermeiren’s core argument addresses Hegel’s critique that Spinoza’s system, allegedly lacking the principle of negativity, collapses the diversity of temporal experience into a purely eternal substance, thereby rendering duration illusory. Although Hegel insists that only a conception incorporating negativity can explain real temporal succession, Vermeiren refutes the view that Spinoza lacks the means to account for genuine temporal diversity. Instead, he shows that Spinoza’s philosophy achieves an account of time and partial knowledge by placing the emphasis on the notion of incompleteness rather than strict negation.
He begins with Hegel’s observation that Spinoza, by positing the single substance called “God or Nature,” appears to eliminate the differentiations constitutive of real change. Hegel interprets this unity as preventing an authentic recognition of temporal succession because nothing is truly separate from God’s all-encompassing activity, leaving no genuine negativity to mark the transition between states. Vermeiren counters this by placing the spotlight on passages in Spinoza where duration is explicitly considered an abstract and inadequate way of perceiving things, yet not a nonentity. Around the opening moments of his talk, he cites Hegel’s argument directly: Hegel describes Spinoza’s absence of negativity as resulting in the illusion of temporality, since all finite modes would be subsumed by God’s eternal activity. Vermeiren shows that Spinoza’s own texts challenge such a conclusion by describing duration not as mere illusion but as something tied to partial or incomplete knowledge and partial causation, both of which remain real aspects of existence.
He further clarifies, at approximately two minutes into his presentation, that Spinoza’s metaphysics contains a consistent framework for understanding duration through the concept of incomplete or inadequate ideas. According to Spinoza, every idea is found in God’s infinite intellect, yet some remain partially formed when considered on their own. This partial status means such ideas exist without the full context or causes that would transform them into adequate expressions of reality. Vermeiren aligns this partiality with passivity, explaining that God’s all-inclusive power nevertheless encompasses actions that, taken in isolation, appear incomplete and thereby give rise to inadequate ideas. These ideas are not illusions: they are genuine but fragmentary expressions of the whole. At around eight minutes, Vermeiren illustrates this by referring to Spinoza’s characterization of abstract or inadequate ideas as “beings of reason” or “mutilated ideas,” so called because they omit essential causal or contextual elements. When one imagines the sun as a small disc in the sky, one lacks supplementary knowledge of the sun’s larger structure and its actual distance, which would complete the picture. The image of the sun as a small disc still truly exists in God’s intellect, but it is integrated into the adequate idea that contains the necessary corrections.
By detailing Spinoza’s account of the imagination, Vermeiren explains that inadequate ideas result from the mind’s tendency to grasp only partial information. The blending of imprints from multiple encounters with external bodies consolidates experience into universal notions (around eleven minutes, he cites how individual encounters with distinct objects morph into a single vague representation), but these abstractions inevitably omit specifics. Their falsity, in Spinozist terms, arises not from conjuring nonexistent entities but from lacking completeness. This logic also underlies Spinoza’s interpretation of durational existence: the mind imagines the temporal passage of events precisely because it retains, in partial form, the record of finite bodies interacting and changing.
He next addresses how this partiality can coexist with the principle that God’s intellect contains only adequate ideas. He reminds listeners, near sixteen minutes, that for Spinoza, the infinite intellect comprehends every idea in full, but the human mind grasps some of these ideas inadequately. The abstract or durational idea of a particular event in time is indeed present in God’s intellect, yet it remains incomplete unless supplemented with the larger network of ideas explaining its full causes and context. These partial ideas persist in God’s eternal intellect rather than being annulled by it, a point that Vermeiren emphasizes when critiquing commentators who suppose that everything finite simply dissolves into the whole. He refers to Spinoza’s famous example of the worm in the blood, illustrating how the worm’s partial perspective mirrors how the finite mind, and finite bodies themselves, occupy places in the broader cosmos without being obliterated by it.
He then shows, around twenty-three minutes, how this analysis provides a precise explanation of the status of duration. Since finite modes experience their own existence as partial, relying on external causes, the imagination constructs a notion of time that tracks these passive states. Spinoza connects passivity in knowledge to passivity in being: an idea is inadequate because its object is explained not by the mind’s essence alone but also by external factors. Duration, in turn, signifies a passivity rooted in finite, partial causation. Vermeiren ties this to Spinoza’s dual categories of activity and passivity, explaining that truly active states align with understanding things sub specie aeternitatis, whereas passive states align with the partial viewpoint that experiences duration.
He further indicates, near thirty minutes, that Spinoza maintains a direct correlation between passivity and durational imagination versus activity and eternity. Duration happens only when something depends on additional causes beyond itself; eternity aligns with any being or idea that requires only its own essence (and God’s infinite attributes) for its self-expression. Vermeiren insists that this dependence on external causes does not negate the reality of duration but rather explains its ontological status as genuine yet incomplete. This position avoids depicting time as sheer illusion while also keeping with Spinoza’s principle that everything is fundamentally in God, whose nature is eternal.
He observes that this same framework clarifies the difference between singular durational minds and eternal intellect. Near thirty-seven minutes, he draws the parallel between inadequate ideas that are partial and complete, adequate ideas existing in God’s intellect. An individual mind grasps phenomena through limited knowledge, generating images that require other ideas to reach full adequacy. Nevertheless, the individual’s partial perspective remains a true component of the totality. From this analysis, it follows that durational existence is equally partial. It constitutes a real mode in Spinoza’s system, existing in God as incomplete, rather than vanishing into the overall completeness of divine activity. When one recognizes that passivity results from partial agency and partial perception, it becomes apparent that durational experience arises from the very same fragmentation.
He completes the exposition by affirming that this parthood does not obliterate a finite idea’s uniqueness. The individual’s inadequate ideas are part of the infinite intellect in a way analogous to how an organ in a body remains distinct while also integrated into the larger organism. He explains how certain parts can be more active or more passive based on how fully they accord with the whole. Near the concluding segments, at approximately forty minutes, he reiterates that the ultimate difference between durational and eternal modes of existence lies in whether something’s essence or definition alone explains its reality. Where a part depends on external causal chains for its identity, it endures in time as a partial entity; where it is self-contained, it exhibits eternal dimensions. Since human minds rarely achieve purely self-contained understanding, their ordinary experiences of time remain rooted in partial, inadequate views, yet persist as real features within the all-encompassing intellect of God.
Throughout the talk, Vermeiren refines Spinoza’s conception of inadequacy, showing that it rests on the notion of being “mutilated” or “incomplete.” An idea that shows something partially is not rendered non-existent once completed by additional information; it simply stands as a fragment that becomes comprehensible when fitted into God’s complete knowledge. Vermeiren’s argument integrates this logic into the question of time, concluding that duration exists as a real, though incomplete, segment of eternity. One may still speak of everything as eternal from the standpoint of the whole, but from the standpoint of finite modes, everything is also durational because finite minds only track realities through partial causal links.
He draws on his extensive research on Spinoza, Leibniz, Bergson, Whitehead, and Deleuze, a project showcased in his recent book, A Geometry of Sufficient Reason. He brings that background to clarify how Spinoza’s metaphysical framework maintains the coherence of an eternal perspective together with the reality of finite, durational experience. The lecture’s focus on partial ideas, passivity, and abstract conceptions exemplifies how duration can be fully included within God’s infinity without being reducible to illusion, thus offering a direct counterargument to Hegel’s claim that Spinoza negates genuine temporal difference. By foregrounding incompleteness rather than negativity, Vermeiren shows that Spinoza accommodates the multiplicity of finite experiences under an overarching eternal domain, preserving time’s significance while upholding the unity of substance.
Vermeiren’s talk ends by reiterating that human existence is necessarily entangled with external causes, limiting the adequacy of one’s knowledge and thereby grounding experiences of passivity and temporality. Since God alone has the complete ideas that supplement every fragmentary perception, individual minds encounter existence as durational and inadequate, even though all is ultimately contained within the eternal intellect. The existence of partial, fragmentary ideas provides the conceptual space for the distinct reality of time, just as partial causation explains passivity. The conclusion is that duration, far from being an outright illusion, enjoys the same status as any other incomplete reality in Spinoza’s ontology: it is genuine, though incomplete, and perpetually supplemented by the entirety of God’s active and eternal intellect. Vermeiren invites further inquiries by offering his contact details, florian.vermeiren@kuleuven.be, emphasizing the ongoing scholarly conversation about Spinoza’s metaphysics, its interrelations with Hegelian thought, and the deeply refined understanding of how eternity and time coexist in the divine intellect.
Florian Vermeiren (KU Leuven) has produced notable scholarship on Spinoza’s metaphysics, especially regarding time, duration, and the status of inadequate ideas. In a recent conference paper titled “The Incompleteness of Durational Existence” (2024), Vermeiren examines Spinoza’s claim that duration – the temporal endurance of finite things – belongs to the realm of inadequate or abstract cognition. Spinoza often suggests that as long as we conceive things in time (one-after-another), we do so imaginatively and incompletely. Vermeiren argues that for Spinoza, durational existence is “incomplete” because it is grasped through the first kind of knowledge (imagination), yielding only partial, confused ideas. By contrast, adequate knowledge conceives things sub specie aeternitatis (under the aspect of eternity), outside the flow of time. In short, Vermeiren’s work highlights how the temporal perspective in Spinoza’s philosophy correlates with incompleteness in understanding, whereas the eternal perspective promises a more complete, adequate insight into reality.
Vermeiren develops this point in his peer-reviewed publications as well. For example, in “A Perspectival Reading of Spinoza’s Essence-Existence Distinction” (Dialogue, 2022), he contends that eternity and duration in Spinoza are not two separate metaphysical realms but rather two ways of understanding the same nature. As he explains, existence “endures” (dure) in time from the human vantage, yet Spinoza indicates that eternity and duration are two manners of comprehending nature, rather than two really distinct aspects of nature. In other words, the difference between viewing something as durational (in time) versus eternal lies in the mind’s perspective: the imagination views things in succession (yielding inadequate ideas of them), whereas the intellect views that same reality through God’s eternal essence (yielding adequate ideas). Vermeiren’s analysis aligns with Spinoza’s own remarks that the eternal is not a separate timeline but the true intelligible being of a thing, seen in complete, atemporal context. Thus, Vermeiren emphasizes that the incompleteness of our durational, temporal experience (and the inadequacy of the ideas derived from it) is a central feature of Spinoza’s epistemology and metaphysics.
Beyond these specific topics, Vermeiren’s broader research on Spinoza (and rationalists like Leibniz) often returns to how finite modes are conceived and how concepts like space, quantity, and power relate to Spinoza’s system. His book A Geometry of Sufficient Reason situates Spinoza in a lineage of thinkers concerned with the structure of reality, suggesting that Vermeiren approaches issues of time and duration as part of Spinoza’s overall metaphysical “geometry” of substance and modes. Vermeiren’s contributions – from conference talks to journal articles – shed light on how duration (time-bound existence) in Spinoza is linked to partial knowledge and metaphysical incompleteness, while true completeness is found in the eternal perspective of adequate ideas.
Simon Gros 
Leave a comment