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The most ad hoc consequence that Leibniz derived from his conception of substance is that substances can only begin at creation and end in annhilation, along with the consequences he in turn derives from this assumption . This assumption is not deducible from the understanding that it is the nature of an individual substance to have a notion so complete that it is sufficient to contain all predicates of the subject to which the notion is attributed; hypothetically, a substance could begin at any point in time and end at any later point in the universe's time-line, so long as its notion is complete enough to contain all predicates of the subject during the past, present, and future of the substance anywhere within that subsection of time. Likewise, it is therefore entirely possible for substances so defined to naturally increase and or decrease, without ever having to be divided or multiplied in violation of their definition. Furthermore, each substance would therefore not necessarily be a complete world mirroring the universe as a whole in their own particular way, but would mirror only the time period of the universe of their own duration (not necessarily coextensive with that of the universe); likewise, each substance would therefore potentially be an incomplete world, as each finite substance would potentially be distinguished from other by their temporal interrelationships as well as by their predicates. Nothing in the definition of substance as initially outlined in his Discourse on Metaphysics prohibits substances from being distinguished from one another solely by their position on the time-line, though it does prevent drawing a distinction between two substances based solely on their position; there can only be one individual substance instantiated for each complete individual concept for the extent of its duration within creation, but every complete individual concept may theoretically re-emerge as different substances with different durations through time (so long as they are never temporally co-extensive with one another) without this violating his initial notion of substance. Stripped of its atemporality, then, the Leibnizean notion of substance might in the future serve as a useful logical tool for interperting the non-spatial world of quantum physics.
It follows from this that while Leibniz's understanding that only geunine unities qualify as real substances continues to hold, its substantial form or soul need not be naturally indestructible except for the duration of time between its own appointed creation and annihilation, though it remains indivisible all the while. Regardless of this change in definition, matter alone (the Cartesian "corporeal substance") cannot be considered a true substances, because its essence is simply its extension and therefore matter is necessarily divisible; a material body remains merely an aggregrate of simple substances under this analysis, rather than anything more fundamentally real, though they are more than merely imaginary phenomena insofar as they are grounded in the simple substances. In accordance with the consequences drawn from his logical notion of substance and doctrine of marks and traces, the simple substances would remain essentially active, consisting of a force for acting and being acted upon - its primitive active and passive powers, respectively. The primitive active force would properly continue to be understood as the law of the series of the simple substance through time, passing from perception to perception through their own internal strivings by the law of their nature from the very beginning of their duration until its very end as also set by the law of their nature. Unlike Leibniz's atemporal constriction of his definition of substance, this critical reconstruction attributes the perception of the duration of any given substance as a modification of all other substances, harmonizing with one another as they represent this phenomena in different ways in accordance with the predicates of each substance just as they would any other phenomena. Temporal duration as a predicate of these other substances is theoretically important in this regard, as their harmonization would be necessary for the intial substance's time-line to be established relative to said other substances, and thus for the re-emergence of new substances with otherwise identical predicates outside of the duration of the given substance's existence. An aggregate of such simple substances would therefore have its spatial extension determined by the harmonization of the temporal durations given for each individual unified component; furthermore, the spatial relations between multiple aggregates to one another would therefore harmonize with the annihilation/re-generation of the simples.