In this paper, after a brief discussion of traditional metaphysics and its guiding principles, we take a look at naturalized metaphysics. There is an agreement in the practice of naturalized metaphysics that it is continuous with science. However, it turns out that this commitment is not enough to define the discipline. Having defined what naturalized metaphysics is, a concrete example drawn from the literature on the philosophy of time is examined thoroughly. The example is taken from Putnam's famous paper on the relation of science to the problem of time Finally, we conclude by saying that naturalized metaphysics is not radically different from the traditional one concerning its methods. Therefore, there is a fundamental vagueness in terms of methods in multiple instances of alleged naturalized metaphysics. Special relativity and the metaphysics of time An interesting case of a philosophical confrontation between physics and metaphysics is the debate over the ontology of time. McTaggart, at the beginning of the twentieth century, argued for the unreality of time (McTaggart, 1908). His argument has resurrected the problem of the dimensionality of the world in metaphysics. After that, three kinds of ontologies have been distinguished: Presentism ( only the present events are real, ) Pastism ( only the past and present events are real, ) and Eternalism ( All past, present, and future events are real. ) In general, the metaphysical debate over these three kinds of ontologies was pursued traditionally, i. e. by a priori argumentation. However, since the 0691 s, the debate found an interesting naturalistic twist: by arising arguments from the relativity of simultaneity in favor of eternalism, physics in general and special relativity, in particular, gained an important role in the debate. 1. Science as the ultimate solution Some philosophers had argued that the problem of the true ontology of time gets its ultimate solution by ( and only by ) physics. The idea was the, there is a well-established scientific theory of space and time, namely the special theory of relativity, which rejects the ontological distinction between past, present, and future events. So, this theory has thought us that we live in a four-dimensional world and there is no more ontological problem concerning time and the determination of future events ( for example, see Gö del, 0696 Rietdijk, 0699 Fitzgerald, 0696 Putnam, 0691 Sider , 91-21 1110 and Saunders . ) 1111 In his influential paper‘ , time and physical geometry ’ , ) Putnam argues given the relativity of simultaneity, since reality is absolute then past and future events, as well as present ones, are all real. 2. Science as a source, not as the ultimate solution In response to Putnam’ s argument, some philosophers objected that, from the relativity of simultaneity, one need not necessarily conclude eternalism. The absoluteness of reality, for example, is an assumption to which one might not be forced to commit ( Sklar1977, 112 0691 ( . ) The idea is that eternalism, presentism, and pastism, as viewed traditionally, are not the only options in the metaphysics of time. A metaphysician can reasonably, develop other metaphysical models of time, consistent with the relativity theory ( for example, see Stein 0691 , Stein and Godfrey-Smith 0660 . ) 0616 3. science as a source of confirmation of rejection As another trend in the literature, there is a tendency to considering the a priori method as a valid way of reasoning in metaphysics. Along this line, some philosophers continued to develop metaphysical models of ontology concerning time, based on the traditional a priori method. However, these philosophers are naturalistic in that they are sensitive to the outcomes of science. They try to show that their favorite metaphysics either get confirmation from science (for example Sider ) 1110 or at least is empirically adequate ( for example Tooley. ) 0661 4. Philosophy as a study in the conditions of possibility of science The fourth approach in ( one might call ) the natural philosophy of time has been exemplified in a work by a famous figure of logical positivism: Hans Reichenbach . ) 0621 ( He argued that some unempirical elements in the relativity theory can be treated as a priori. However, this differs from Kant’ s reasoning in that these a priori elements are not necessary, but conventional. This conventionality appears, especially, in the standard definition of simultaneity presented by Einstein. This definition, Reichenbach argues, rests on the unverifiable assumption that the one-way speed of light is ( in a vacuum ) a constant in all directions. Appealing to the conventionality thesis, some philosophers had tried to argue in favor of eternalism ( see for example Petkov 0616 and , ) while others 1111 attempt to exploit the in principle impossibility of determining empirically the one-way speed of light to defend their noneternalistic metaphysics against Putnam's argument ( Tooley, 0661 Cohen. ) 1109 Conclusion we conclude by saying that naturalized metaphysics is not radically different from the traditional one concerning its methods. Therefore, there is a fundamental vagueness in terms of methods in multiple instances of alleged naturalized metaphysics.