Transcendental Realism
Transcendental realism argues that, if scientific knowledge is to be possible, it must be about "something" and this "something" may be relatively hidden parts of reality, not only the surface or measurable parts. Therefore, transcendental realism argues that reality is layered, with a transcendental/hidden part as well as a non transcendental/measurable part. Real things which we may not be able to see or hear or otherwise observe include "potentials" or even "absences", such as the absence of health. They also include real "generals", such as the general category of cutlery, even though one cannot hold a "cutlery" in one's hand so to speak, one can only ever hold knives and forks. Similarly, Bhaskar argues that there are real emergent beings, such as ecosystems or societies, even though one cannot technically see "ecosystems" or "societies", as one can only see the organisms that make them up. As Bhaskar explains further in A Realist Theory of Science (p. 216) "Scientifically significant generality does not lie on the face of the world, but in the hidden essences of things". For example, emeralds are not green because every emerald we have ever seen is green, but because the hidden chemical structure of emeralds means that they could not, all things being equal, be anything other than green. If a gemstone does not look green, even if it is an emerald, because it is being viewed through a red filter (that is, if all things are not equal), this does not detract from its essence as an emerald. That is, there is a real general to which we refer when we talk about emeralds, and underlying this real general is a real, essential reason - Bhaskar calls it the alethic truth - for why the general exists.
However, some people mistakenly think that because Bhaskar talks about essences he means that there is some kind of absolute truth untouched by humans. This is not the case, as there is always a social element to our understandings of reality, whether it is material or immaterial. To clarify this human involvement in naming and categorising reality, Bhaskar says that reality has intransitive and transitive dimensions. Specifically, there are some aspects of reality, known as intransitive reality, that exist even when humans are not there to interpret them; and there are some aspects of reality, known as transitive reality, that exist because they are in relation to humans and their meaning making. All knowledge includes both intransitive and transitive aspects of reality, which means that there is no absolute knowledge, untouched by human understanding. The concept of the intransitive and transitive aspects of reality effectively avoids the dichotomy between natural science and hermeneutics, keeping the most important aspects of both approaches (Bhaskar Reality and its Depths, p. 84).
​
Linked to the transitive part of reality is Bhaskar's idea, fully developed in his later books, that the human reason for naming or arriving at factual knowledge is important. For instance, whether a tomato should be classified as a fruit or vegetable depends on who is asking. For a biologist, who is interested in how plants reproduce, a tomato is technically a fruit because it has internal seeds. For a chef, who is interested in making tasty food, a tomato is a vegetable because its low sugar levels make it unsuitable for putting into a fruit salad. Another way of saying this, is that there are no abstract universals (such as some ideal-typical perfect fruit, which tomatoes either do or not match). Instead, there are concrete universals (such as a concrete group of things we call fruit because they satisfy an objective for calling them so). All fruits will have some things in common with all other fruits and yet each fruit will have a history and a place where it was grown so that there is a way in which each fruit is unique. This approach to seeing the world of categories has been useful in helping to make sense of the complexities of gender identity in a way that avoids a simplistic dichotomy between men and women based on ideal-typical ideas of the perfect man or woman; and thus it gives a philosophical justification for allowing greater variation in how we label people. It thus allows for, or gives an ontology to, the intersectional view of people as first described by Kimberlé W. Crenshaw, so that we can be complicated without contradiction. As Bhaskar (Enlightened Common Sense, p. 92) explains, "It is the concrete universal that allows an English soccer fan to say: ‘Though I was born in Chelsea, I support Arsenal".
​
Reality is layered
​
A consequence of the existence of transcendent and non transcendent aspects of reality is that it is appropriate to think of the world as being layered, with real deeper structures and mechanisms that are the explanation for surface, measurable reality. Bhaskar includes "events" or "manifest phenomena" as part of this layered way of describing the world. Events sometimes consist of "constant conjunctions of events", known statistically as "correlations". Such conjunctions are rare because they are only found in closed-systems which humans must usually create in laboratories. Because such closed systems are not beset by unpredictable, uncontrollable conditions, they allow us to see regular constant conjunctions of events that suggest causation. Therefore, one way (but not the only way) that we can understand and explain the world is by closing off the system to better see which conditions are necessary for something to happen, and by putting all of this information together to arrive at theories about the underlying structures and mechanism that are the basis for our measurements. This approach to reality, that argues that reality consists of real mechanisms, actual events and their constant conjunctions, and empirical measurements is illustrated below using the study of the factors that affect photosynthesis in plants (Figure 1, at the bottom of the page). When constant conjunctions of events and their empirical conditions are assumed to be the only level of reality of interest to scientists, we have actualism, "expressed most starkly in the Humean theory of causal laws" (Bhaskar, Enlightened Common Sense, p. 27). Actualism underlies the idea that only science based on statistical correlations counts as real science. Bhaskar's critical realism embraces the "empirical" and the "actual events" parts of reality, but goes beyond them to include that part of reality that includes "structures and mechanisms" too. Structures and mechanisms include events, and events include empirical things. Empirical things do not exist other than as the observable traces of, or as constituents of, events, mechanisms and structures.
​
Retroduction
​
Since transcendental things, namely structures and mechanisms, cannot be measured, but rather must be known about through their effects, a different epistemology is needed to know about them, compared to the epistemology used to know about non transcendental, material entities. Material entities can often be studied in the context of experimental science, which is associated with the logics of induction and deduction. Roy Bhaskar argued that, in order to apprehend the transcendental reality of structures and mechanisms, scientists must add another logic - the logic of retroduction, sometimes called abduction - to their repertoire. Retroduction is what happens when a person surmises what-must-have-been to explain what is. That is, retroduction is used by scientists to surmise the existence of the transcendental structures and mechanisms that explain the empirical layer (what we can measure) and the actual layer (of sometimes measurable constant conjunctions of events).
Bhaskar did not claim that this is something altogether new; rather he said that scientists are already using retroduction, and that this approach to epistemology is already implicitly present in scientists' everyday practice (they just do not mention it when they talk about what they were doing). To give an example of retroduction, the current changes that we are seeing in average weather patterns over the globe have been retroductively explained as being due to the net effect of human industrialisation. Another competing retroductive explanation is that climate change is due to natural processes, unrelated to human activity. Critical realists use what they call judgemental rationality to compare such competing claims, choosing to run with the claim that explains more of the evidence. Note that, in terms of the climate change debate, neither of the claims for or against the effect of humans on the climate can be checked experimentally in a laboratory. Since much of what experimental natural scientists are interested in can be isolated in a laboratory, most of them had not noticed that there was an absence in their philosophy of science. This absence becomes glaring when scientists try to research things that cannot be placed into a laboratory. In the case of social science and ecology, their subject matter cannot be placed into laboratories because they are emergent from the individuals that form the material basis of their existence. That is, ecosystems are emergent from the activities of plants and animals; and societies are emergent from the activities of people and we cannot test whole ecosystems or whole societies in a laboratory. We can only figure out what is happening in ecosystems and societies if we use retroduction to think about the underlying, emergent, structures and mechanisms that have led to the events and entities that we can witness and measure. When natural scientists tried to apply positivist scientific principles to situations that could not be closed off in laboratories, that is, to open systems, things got tricky. Such open-system situations are unavoidable in the social and ecological sciences, leading to the situation in which they cannot be conducted experimentally, and hence to the claim that they are not scientific at all.
​
Hermeneutics
​
However, some social scientists dealt with the accusation that social science is not proper science by saying that social science is totally different from mainstream science. They said that it has a different subject matter (human conceptualisations and meanings) and that therefore it must be carried out with different epistemological rules, namely those that involve qualitative "interpretivist" research rather than quantitative research. That is, they argued that we can only know about what is going on in societies by talking to people who can then say what things mean to them, and that we cannot therefore use the methods of positivist science to do social science. This is roughly the hermeneutic approach to social science. Whilst this approach was not altogether unsuccessful, because people naturally use retroduction when they are making meaning of their world, it was ultimately unsatisfactory because there was no way to choose between explanations. That is, there was no formal requirement for judgemental rationality and no formal acknowledgement that the theories that people might arrive at in their meaning making processes were actually about anything real. Rather, they were simply seen as unique instantiations of opinions, without any chance of moving into the realms of general knowledge about how things work in societies, that is, they were not seen as being about the transcendental structures and mechanisms that explain society and thus the possibility of critique was denied (Bhaskar, Enlightened Common Sense, p. 183).
From a democratic perspective, hermeneutics gave people the valuable freedom to come up with their own knowledge; but their knowledge was often not taken seriously as it was not seen as scientific or about anything real. This was devastating for those people who wanted to critique the current way that the world works, as any critical claims they might make could easily be disregarded as being mere opinion, with no basis in reality, that is, essentially unproven and unscientific, and therefore not able to justify emancipatory action. For instance, the well-known advocate of empirical science, Karl Popper, said that there was no difference between the theories of Marx and the theories of astrology; and in terms of the climate change debate, many climate change deniers argued that the theory of climate change is no more than an opinion and not real science because its models cannot make testable predictions. What activists needed was a philosophy of science that would allow their critical theories to be taken seriously, and this is what Roy Bhaskar's transcendental realism offers them.
​
Figure 1: Illustration of the idea that reality consists of real mechanisms, actual events and their constant conjunctions
