Ian Hacking, in one of his seminal works, Representing and Intervening (R&I) (1983), provides a persuasive proposal regarding the definition of the real, especially with respect to the theoretical entities. According to him, the real is associated with any hypothetical entity which can be 1) manipulated and 2) exploited in order to affect and comprehend other parts of the world. That is to say, if a theoretical entity x, let us say it is an electron, after being manipulated does not affect some part of another theoretical entity y, let us say it is the electric charge on the niobium ball, it can be reasonably stated the entity investigated is not real. At first glance, it seems compelling. Who would deny the existence of something we can play with? However, up to a point, although there are some useful conceptual chains which could be appropriated for supporting scientific realism, attributing the real to entities through manipulation is not that easy.
Hacking’s argument is based on the weakness of representation, or theories in the scientific context, in attributing the status of the real to the theoretical entities. Hacking provides a thick explanation of the issue, particularly in the chapter break. It could be reformulated into one line though: representation is plural, and, therefore, as long as it is perceived as the foundation to establish reality, two idealistic consequences will emerge, namely, either 1) all representations are real or 2) there is no reality at all. Old realism, or theoretical realism, eagerly fights on the field of representation so as to discover which theories are true. Hacking strongly rejects the position mentioned, “There is nothing there” (145), he says.
The rejection stems from Hacking’s speculation that representation is the essential part of human nature. Instead of homo faber, for Hacking, humans are homo depictor; they always represent something. However, as opposed to the subjective and personal representation of empiricist, representations are external and public. They could be accessed and produced, ranging from simple physical things, such as scratch, to abstract complicated notion, such as the law of gravity. Consequently, what Kuhn says as incommensurability and dissociation, or what Heinrich Hertz says as incomparable three physical models which have their own advantages, seemingly turn out to be inevitable. There are numerous different models and hypothetical theories opposing each other which could be formulated for explaining phenomena.
Hacking contends that it is a pressing matter to constitute some indicators, which do not depend on theoretical representation, to tackle the problem, and, for Hacking, it is the manipulation itself. Specifically, what Hacking means by manipulating is obtaining causal understanding of theoretical entities so as to set up a device which could interfere with other hypothetical entities. “We know the effect, we know the cause, and we use it to understand other things.” (24) To put it another way, Hacking’s position stands for three main ideas, 1) causal understanding of theoretical entities, 2) devices, 3) interventions. When those three components are completely executed, it will be absurd to not perceive it as not real. For we are doing with it, the level is different from comprehending it. However, ontologically, Hacking has not utterly answered traditional challenge against scientific realism.
Firstly, Hacking’s interpretation of the possibility of theoretical entities within the scientific framework in general. To explain the compelling side of scientific realism, or, specifically, in his term: entity realism, because of his faith to entity is heavier than to theory, Hacking explicitly exemplifies two scientific cases from the experiment of natural sciences. Firstly, regarding the manipulation of the electron to lower the charge on the niobium ball so as to discover the status of the quark, and secondly, as to the employment of a device well-known called PEGGY II manipulating electron to understand weak neutral current. Based on those cases, Hacking asserts the existence dimension of the electron since it can support us to find out new information with respect to other hypothetical parts of the world, which in these cases are quark and weak neutral current.
At this point, we can see the strong point of Hacking’s argumentation. Fake theoretical entities often used for discounting scientific realism, such as Phlogiston or Mendelian Gene, cannot be exploited anymore since we had not obtained technology which could forge the entities in question at that time. We lacked the manipulative side of technology. Recently, we have more capability to point out the existence of some entities.
Hacking relies his argument too much on the advancement of technology. It could be concerned as risky for what occurred on Phlogiston and Mendelian Gene nevertheless could still go on toward the new theoretical entities verified by cutting-edge technologies. There are still possibilities that new confirmed theoretical entities are just artifacts, meaning they are not natural kinds or their causal powers are determined by other entities. David B. Resnik in “Hacking’s Experimental Realism” has the similar doubt because, at that time, scientists have rather assumptions regarding the kind side of Phlogiston and Gene. Nevertheless, history shows the inverse. Although they are not fictional entities, they are artifacts.
Counting on the advancement of technology implies that we could improve our technology to the new level because only with this presumption we could falsify the experiment carried out in the past. It brings us back to the problem of pessimistic meta-induction, but in the domain of the progress of technology to reveal the world. Using the same logic, it seems not persuasive to hold that electron will be always standing as a natural kind rather than turning out to be just artifact since there is a possibility the new device could revise our understanding toward the source of causal power. Providing that the doubt is countered with undermining the advantages of possibility reasoning, Hacking argument might backfire as, with that move, it could lead Hacking to degrade his position in accomplishing the stability of the realness of the entities in the realist position.
Still in the same problem, as elaborated clearly by Elsamahi in “could theoretical entities save realism?” (1994), if the electron turns out to be an artifact, will the experiments renounced by Hacking change the result? There are only two answers, firstly, it does not change at all, or it could change with different interpretations. Both of the options do not uphold Hacking claims as regards the stability of the realness of the electron as an entity. The moral of the possibility is that it looks convincing that experiments do not entail ontological commitment. Conversely, it runs with mathematical formulations, as well as with certain theoretical background, programmed on a device to gain specified results, which, to some extent, has been predicted.
Secondly, the use of causal laws and the status of the theories in the experiments. Hacking has interesting arguments here with his two examples. Firstly, imagine some theorists having different theoretical understanding are gathered to work together in an experiment. It is clear that their differences would not change the position of the entity which is going to be manipulated. Secondly, given that laboratory assistants are taught the way in which tracking down the reaction of positrons. It is highly probable that they would find the entity showed by the microscope, since it is already epidemic in the scientific practices, even if they do not have any understanding regarding the theory behind those phenomena.
In that position, Hacking utilizes theories and tools manufactured with theories as instruments to reach internal constitution of the world. The tendency is extremely realist and somewhat ignores the strong protest of anti-realist toward the traditional maneuver dividing and undermining epistemological field from metaphysical one. Hacking leaves theories when he already has got the entities, but the leap is fairly difficult to catch. The first reason is that the understanding of the scientist toward causal laws doubtlessly based on theoretical understanding, and the second reason is that Hacking, to answer the first issue, seems not giving ontological justification that entities founded and subsequently forged by certain scientific devices are not merely consequences of the rule installed on that device. If it is the case, scientists without theory could nevertheless use the device and find something. However, the problem lies in the source of the entities. Since while it is apparent to say that the entity is theory-free, it is not the case for the device itself. A device would not exceed the capability which programmed to it. And only with that limit, they could find something. In other words, we could still be skeptical even if we know the causal laws of an entity and play it by using a device.
Regardless the notion presented by Hacking looks promising, two ontological doubts above, namely the dependencies toward scientific progress and the position of entities in the face of theories and devices, has demonstrated that crude attribution of the real to things is not as simple as to show its manipulative side, especially in the theoretical fields. Something which could be manipulated is not inevitably real. They probably are just residue from other entities which are more fundamental but have not comprehended yet. The complexity arises because representation is not only external and public but also historical. As long as entities and manipulation cannot go along with the complexity of the structure of human understanding and their historicity, the effort to reach the contradictive, namely the independence of the world, will never be accomplished. Hacking provides us with the examples from the history of sciences. However, we should have foundations which are more stable for realism. The only way we can reach that place is through structures and assumptions of the theories itself. Hacking reveals the history of the scientific practice, but he does not cope with the stable foundation of the possibility of historical examples he uses.
 Ian hacking, Representing and Intervening: Introductory Topics in the Philosophy of Natural Science (Cambridge: Cambridge University Press, 2010).
 David B. Resnik, “Hacking’s Experimental Realism”, Canadian Journal of Philosophy, 24, no. 3 (1994) 408.
 Boaz Miller mentions about the similarity of Hacking argument with non-miracle argument. The point is Hacking still using convergence and abductive reasoning in some way. Boaz Miller, “What is Hacking’s argument for entity realism?”, Synthese, 193, (2016) 995.
 Mohamed Elsamahi, “Could Theoretical Entities Save Realism”, PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association, (1994) 176.