What does it mean to say that something is “temporal” or that something “exists” in time? What is time? And how should we interpret the “ontology” of time? One important strand in twentieth century thought and the philosophy of time has given these fundamental questions a neat and tidy set of influential answers—according to this view, time itself is understood to be a kind of series, and the basic ontology of time is taken to consist of events, together with either the tenses, which get interpreted as special sorts of second order properties known as “A properties” (i.e. the properties of being either Past, Present, or Future), or with special sorts of second order relations, known as “B relations” (i.e. the relations of “earlier than”, “later than”, or “simultaneous with”) which are typically referred to as tenseless. According to this particular view, taken together, A properties and B relations are understood to exhaust the ontology of time. This is an interpretation that has been typically found throughout much of the philosophical literature on the metaphysics of time throughout the twentieth century despite the fact that both of these prospective temporal ontologies had already been shown early on to face a major problem—McTaggart's paradox (1908). According to the paradox, regardless of whichever ready-made ontology we ultimately opt for, we still are led to the same ineluctable conclusion—that time is unreal. For the better half of the twentieth century, philosophers of time, science, and language have struggled with this paradox in different ways, in various attempts to wrest their own preferred categories of temporal being from its grasp, in order to redeploy them in the course of developing a number of competing metaphysical accounts of time, which get characterized technically, as either “A” or “B” theories of time, depending primarily on whether their respective ontology remains either tensed or tenseless. What has thus emerged over the course of the past century, has been a growing preference among philosophers for interpreting temporal ontology along strictly A theoretical or B Theoretical lines, which has rendered this particular strand of thought a highly influential one with respect to a large portion of our contemporary understanding of temporal ontology, which remains one that ultimately boils down to a choice between A properties or B relations, as evidenced by Broad (1923), Smart (1963), Prior (1970), Mellor (1985), Oaklander and Smith (1994), Inwagen and Zimmerman (1998), Smith and Jokic (2003), Sider (2011), Tallant (2013), etc. Further evidence of this view can also be located not just within both A and B theories of time—which include both tensed and tenseless theories—but also within theories of presentism and eternalism, as well as within recent relationalist and substantivalist accounts of time. In the dissertation, it is argued that a common background assumption within these various accounts of time, perhaps one of the most basic and most wide-spread, turns out to be fallacious. More precisely, an extended argument is developed against the common and basic assumption found within these views that it is appropriate to depict time as consisting of either an A series or a B series in the first place. This metaphysical assumption is referred to as the “SER thesis”. The dissertation aims to show that any such serialized interpretation of time fails to be sufficiently distinguishable from what are merely formalized spatial representations or spatializations of time, and that when viewed from the standpoint of developing a viable metaphysics of time, any such formalized spatializations ultimately appear to result in something like a contradiction. Some objections are then raised to this main line of argument, where it is further shown, that the most intuitive strategies for replying to it are unsuccessful in the end, and serve only to supply us with various ways of masking the real problem, since each of these strategies seem themselves to commit some form of the ignoratio elenchi or red herring fallacies. In the remaining portions of the dissertation, a revisionary approach to the question of temporal ontology that seems capable of avoiding some of these problems is briefly sketched out. This approach employs the resources of a hermeneutic phenomenology of temporality to try and help us get outside of the standard view that is supplied by the A-B tradition and provide us with an alternative starting point. This approach draws heavily from the work of McTaggart's early twentieth century contemporaries Henri Bergson (1889) and Martin Heidegger (1927).