Nursing Inquiry 2012; 19(1): 6–17
Feature
A critical realist approach to
knowledge: implications for evidence-
based practice in and beyond nursing
Stuart Nairn
University of Nottingham, Derby, UK
Accepted for publication 27 May 2011
DOI: 10.1111/j.1440-1800.2011.00566.x
NAIRN S. Nursing Inquiry 2012; 19: 6–17
A critical realist approach to knowledge: implications for evidence-based practice in and beyond nursing
This paper will identify some of the key conceptual tools of a critical realist approach to knowledge. I will then apply these prin-
ciples to some of the competing epistemologies that are prevalent within nursing. There are broadly two approaches which are
sometimes distinct from each other and sometimes inter-related. On one side, there is the view that all healthcare interventions
should be judged on the principles of randomised controlled trials and the other is a preoccupation with language in which
healthcare interventions are subjected to a discursive interrogation. These debates are configured through the idea of a hierar-
chy of knowledge that is accorded uncritical acceptance by some and virulent distaste by others. I will argue that the notion of
hierarchy is problematic and is largely argued for in unproductive epistemological terms. What is required is a shift towards a
theory that emphasises the contextual nature of the ways that knowledge is produced and disseminated. In other words, there is
no single hierarchy of knowledge, but there are multiple hierarchies of knowledge.
Key words: critical theory, evidence-based practice, mixed method, nursing theory, poststructuralism.
Historically, there has been a tension between science and This anxiety that science, and in the context of health-
philosophy which began to emerge more explicitly during care the medical model, closes of knowledge, is deterministic
the enlightenment when science was referred to as natural and reductionist in character, is a central concern for nurses
philosophy (Thorne 2009). The gradual development of a who have an ongoing commitment to holistic care and to
conflict between science and philosophy is based on science’s multiple sources of knowledge rather than to a restrictive sci-
propensity for prediction and experimental control. The entific one. But this anxiety is also associated with a general
openness of philosophical discourse is closed by a preoccupa- critique of knowledge as a source of power and influence,
tion with methodological robustness and a commitment to the recurrent suspicion that the accumulation of knowledge
the objective world and its erasure of the subjective and con- simply sets up artificial parameters of what it is possible to
textual aspects of knowledge. By the early nineteenth century include as legitimate (Foucault 1972). Thus, nurses lack
therefore the common view of science was that: influence, are a subordinate profession, but if we turn our
knowledge base into a scientific discourse then we will gain
You can call a body of knowledge science only once you’ve
decided it shouldn’t be called philosophy, and scientists, sim- influence and status, which it is then assumed will improve
ilarly, are otherwise learned people who maintain a princi- patient care (Davies 1995).
pled silence on matters of ontology and morality and It is in the contentious area of evidence based practice
politics and God (Thorne 2009, 119).
(EBP) that this debate has become particularly intense, pro-
ducing a mixture of debate and in some cases angry
Correspondence: Stuart Nairn, Derby Education Centre, School of Nursing,
exchanges (Porter and O’Halloran 2009). It is the purpose
Midwifery and Physiotherapy, University of Nottingham, London Road Community of this paper to analyse these arguments from a broadly criti-
Hospital, Derby DE1 2QY, UK. E-mail: <stuart.nairn@nottingham.ac.uk> cal realist perspective. This approach offers the possibility of
2011 Blackwell Publishing Ltd
, Critical realism and nursing knowledge
finding a way through this debate, which incorporates a real- kar the purpose is to re-orientate theory towards ontology.
ist approach to knowledge. It is unlikely and indeed not my The tendency for both theories is to reduce ontological ques-
intention to please everyone and there are some arguments tions to epistemological ones or to confuse our descriptions
in the literature that I believe are unhelpful and should be of the world with the world itself, the so called epistemic fal-
rejected, but the central tenets of critical realism and its lacy. So, positivism is preoccupied with developing robust
prioritisation of ontology over epistemology offers a route methods, axiomatic rules of enquiry that are usually statisti-
into a relational approach to knowledge that incorporates a cal, as a means of accessing precise knowledge about the
pluralist approach to finding out about the world alongside world, while hermeneutics is often focused on a self-referen-
a realist commitment to the structural properties of both the tial preoccupation with the endless play of language as a sub-
natural and the social world. This is not to suggest that there stitute for their erasure of the real. Both are ways of
are no other realist ways of addressing these problems (see knowing, strategies for making sense of the world. While the
Niiniluoto 2002, chapter one), but the purpose of this paper former is committed to accessing the world, it nonetheless
is to outline the possibilities of a critical realist approach. accords the methods employed as determinants of how the
This paper is structured in the following way. I will start world is, it therefore has a tendency to erase ontology or the
with a general overview of ontology from a critical realist per- epistemological trumps the ontological. Interpretivists adopt
spective. I will then examine how the competition between a variety of approaches to the problem ranging from a ques-
different epistemologies is addressed in the literature. First, tioning scepticism to a complete rupture between concept
I will look at how causation, when reduced to a set of empiri- and object that can sound perilously close to a denial that a
cal regularities, can produce a reductionist account of knowl- world even exists outside our perceptions of it.
edge. Second, I will address the strengths and limitations of The central problem for critical theory, whether in its
focusing on language and the discursive. Finally, I will situate realist or non-realist forms, is the relationship between how
these ideas within the idea of a hierarchy of knowledge and we describe the world and the world itself, between concept
how a critical realist account might tackle the notion of a and object. For critical realism maintaining the category dis-
hierarchy. I will cover a number of diverse theories and will tinction is essential and is summed up in the terms such as
doubtless oversimplify the nuances and tensions within these the intransitive and the transitive. The intransitive is equated
theories. For example, I have not addressed the extensive lit- with ontology and a real world of objects with their own cau-
erature on mixed methods approaches to research which sal powers and structures. These are not inert objects, the
attempt to acknowledge many of the nuances of nursing real changes, social structures change and mountains erode,
knowledge. However, the main purpose of this paper is to but they nonetheless occupy a single world and are therefore
grapple with the central tenets and the theoretical not part of multiple worlds as poststructuralists are prone to
approaches of these theories and the tensions between argue. The transitive, however, is multiple and relativist and
them. Finally there is an extensive literature in this area and is associated with epistemology, it is related to how we make
I will be addressing only a fraction of those writers who have sense of the world and crucially is situated within certain
examined this issue, but my main purpose is to develop an socio-historical contexts.
approach that makes EBP and nursing knowledge more gen-
erally, usable for nursing practice. The empirical, the actual and the real
CRITICAL REALISM AND ONTOLOGY Underpinning this distinction is the notion of a stratified
ontology, which has two elements: first, the empirical, the
The relationship between ontology and actual and the real and second the way that these concepts
epistemology operate within different domains of the real. The empirical,
the actual and the real are central to Bahskar’s assertion of a
The relationship between epistemology and ontology is non-positivist approach to scientific knowledge. The empiri-
important to critical realism. Ontology is the world as it is, cal is simply what a person perceives from their senses, what
the constituents of the world, how it is made up, while episte- they see and feel, what they experience. The actual exists on
mology is concerned with the ways we can adopt to access the level of events, what actually happens or occurs and the
knowledge about the world. Bhaskar’s (1998, 2008a) central real is the identification underlying mechanism that may or
arguments about ontology are to critique both positivist and may not occur. So for example I may, on an empirical level,
hermeneutic approached to knowledge. They both adopt experience a heart attack or may observe an individual hav-
epistemological approaches to knowledge, whereas for Bhas- ing a heart attack, or I may identify how many heart attacks
2011 Blackwell Publishing Ltd 7
