Lucretian atomism, despite its materialist ambitions, institutes a foundational blockage. The atom, the indivisible 'seed of things,' operates as a closed, self-identical unit. This model of discrete entities moving in a void establishes an ontology of points and positions, fundamentally at odds with a philosophy of flows and relations. It presents a universe built from unchanging blocks, a kind of metaphysical Lego set where novelty is merely recombinatorial.

From a Deleuzian perspective, this is an arborescent structure parading as a plane of immanence. Each atom is a root-point, a fixed identity. True materialism, however, requires an ontology of relationality, where entities are not pre-given but emerge from the interplay of differential forces and intensities. The Lucretian atom cannot account for the fluidity of assemblages or the intensive properties that arise from their connection. It offers a quantitative world of collision and aggregation, missing the qualitative transformations that define reality as a process.

The atomic swerve, or clinamen, is often presented as the engine of novelty and freedom within the Epicurean system. It is Lucretius's solution to Parmenidean stasis and Democritean determinism, the minimal deviation that allows atoms to collide and form complex bodies. Yet, this swerve is not a true line of flight. It is a contained and predictable unpredictability, a mechanism that ultimately serves to perpetuate the system of atomic aggregation rather than escape it.

A line of flight creates new territory; it is a creative deterritorialization that produces a new mode of existence. The clinamen, by contrast, merely introduces enough randomness to ensure the existing atomic elements can combine. It doesn't challenge the integrity of the atoms themselves. It is a micro-exception that proves the macro-rule, introducing a flaw that makes the machine work. This establishes a transcendental principle—an external rule of deviation—that governs the immanent interactions, betraying the radical immanence it purports to champion.

The Lucretian theory of vision and thought relies on 'simulacra'—thin films of atoms shed from the surface of objects. These eidola travel to the eyes and mind, creating perception. This is a classic model of representationalism, where thought is a copy or image of an external reality. The mind becomes a passive receptacle for images, and truth becomes a matter of correspondence between the image and its origin.

This framework traps thought in a mimetic function, ignoring its productive capacity. It fails to see perception and thought as active, creative processes that participate in the world rather than merely reflecting it. The simulacrum is an intermediary that establishes a gap between mind and world, a gap that a philosophy of immanence seeks to close. Thought does not represent the world; it is an event within the world, a flow of intensity co-extensive with all other flows.

By positing the 'seeds of things' as fundamental, Lucretius locks his ontology into a state of arrested development. His materialism is ultimately one of substance, not process. It fails to grasp that the universe is not made of things, but is a dynamic field of differential relations. Emergence is not the aggregation of pre-existing parts, but the continuous creation of novelty through the interaction of flows. Lucretius's atoms are a form of transcendental fixity, ideal forms that float unchanging through the void, undermining the radical immanence his poem otherwise strives for. The system can only ever be the sum of its parts, never more.