Phenomenology originates in philosophical traditions that evolved over centuries; however, most historians credit Edmund Husserl for defining phenomenology in the early 20th century . Understanding some of Husserl’s academic history can provide insight into his transcendental approach to phenomenology. Husserl’s initial work focused on mathematics as the object of study , but then moved to examine other phenomena. Husserl’s approach to philosophy sought to equally value both objective and subjective experiences, with his body of work ‘culminating in his interest in “pure phenomenology” or working to find a universal foundation of philosophy and science .’ Husserl rejected positivism’s absolute focus on objective observations of external reality, and instead argued that phenomena as perceived by the individual’s consciousness should be the object of scientific study. Thus, Husserl contended that no assumptions should inform phenomenology’s inquiry; no philosophical or scientific theory, no deductive logic procedures, and no other empirical science or psychological speculations should inform the inquiry. Instead, the focus should be on what is given directly to an individual’s intuition . As Staiti recently argued, this attitude towards phenomenology is akin to that of ‘a natural scientist who has just discovered a previously unknown dimension of reality .’ This shift in focus requires the researcher to return ‘to the self to discover the nature and meaning of things .’ As Husserl asserted: ‘Ultimately, all genuine and, in particular, all scientific knowledge, rests on inner evidence .’ Inner evidence—that is, what appears in consciousness—is where a phenomenon is to be studied. What this means for Husserl is that subjective and objective knowledge are intimately intertwined. To understand the reality of a phenomenon is to understand the phenomenon as it is lived by a person. This lived experience is, for Husserl, a dimension of being that had yet to be discovered . For Husserl, phenomenology was rooted in an epistemological attitude; for him, the critical question of a phenomenological investigation was ‘What is it for an individual to know or to be conscious of a phenomenon ?’ In Husserl’s conception of phenomenology, any experienced phenomenon could be the object of study thereby pushing analysis beyond mere sensory perception (i. e. what I see, hear, touch) to experiences of thought, memory, imagination, or emotion .
Husserl contended that a lived experience of a phenomenon had features that were commonly perceived by individuals who had experienced the phenomenon. These commonly perceived features—or universal essences—can be identified to develop a generalizable description. The essences of a phenomenon, according to Husserl, represented the true nature of that phenomenon. The challenge facing the researcher engaging in Husserl’s phenomenology, then, is:
To describe things in themselves, to permit what is before one to enter consciousness and be understood in its meanings and essences in the light of intuition and self-reflection. The process involves a blending of what is really present with what is imagined as present from the vantage point of possible meanings; thus, a unity of the real and the ideal .
In other words, the challenge is to engage in the study of a person’s lived experience of a phenomenon that highlights the universal essences of that phenomenon . This requires the researcher to suspend his/her own attitudes, beliefs, and suppositions in order to focus on the participants’ experience of the phenomenon and identify the essences of the phenomenon. One of Husserl’s great contributions to philosophy and science is the method he developed that enables researchers ‘to suspend the natural attitude as well as the naïve understanding of what we call the human mind and to disclose the realm of transcendental subjectivity as a new field of inquiry .’
In Husserl’s’ transcendental phenomenology (also sometimes referred to as the descriptive approach), the researcher’s goal is to achieve transcendental subjectivity—a state wherein ‘the impact of the researcher on the inquiry is constantly assessed and biases and preconceptions neutralized, so that they do not influence the object of study .’ The researcher is to stand apart, and not allow his/her subjectivity to inform the descriptions offered by the participants. This lived dimension of experience is best approached by the researcher who can achieve the state of the transcendental I—a state wherein the objective researcher moves from the participants’ descriptions of facts of the lived experience, to universal essences of the phenomenon at which point consciousness itself could be grasped . In the state of the transcendental I, the researcher is able to access the participants’ experience of the phenomenon pre-reflectively—that is ‘without resorting to categorization on conceptualization, and quite often includes what is taken for granted or those things that are common sense .’ The transcendental I brings no definitions, expectations, assumption or hypotheses to the study; instead, in this state, the researcher assumes the position of a tabula rasa, a blank slate, that uses participants’ experiences to develop an understanding of the essence of a phenomenon.
This state is achieved via a series of reductions. The first reduction, referred to as the transcendental stage, requires transcendence from the natural attitude of everyday life through epoche, also called the process of bracketing. This is the process through which the researchers set aside—or bracket off as one would in a mathematical equation—previous understandings, past knowledge, and assumptions about the phenomenon of interest. The previous understandings that must be set aside include a wide range of sources including: scientific theories, knowledge, or explanation; truth or falsity of claims made by participants; and personal views and experiences of the researcher . In the second phase, transcendental-phenomenological reduction, each participant’s experience is considered individually and a complete description of the phenomenon’s meanings and essences is constructed . Next is reduction via imaginative variation wherein all the participants’ descriptions of conscious experience are distilled to a unified synthesis of essences through the process of free variation . This process relies on intuition and requires imagining multiple variations of the phenomenon in order to arrive at the essences of the phenomenon . These essences become the foundation for all knowledge about the phenomenon.
The specific processes followed to realize these reductions vary across researchers engaging in transcendental phenomenology. One commonly used transcendental phenomenological method is that of psychologist Clark Moustakas, and other approaches include the works of: Colaizzi , Giorgi , and Polkinghorne . Regardless of the approach used, to engage rigorously in transcendental phenomenology, the researcher must be vigilant in his/her bracketing work so that the researcher’s individual subjectivity does not bias data analysis and interpretations. This is the challenge of reaching the state of the transcendental I where the researcher’s own interpretations, perceptions, categories, etc. do not influence the processes of reduction. It is important to note that modern philosophers continue to wrestle with Husserl’s notions of bracketing. If bracketing is successfully achieved, the researcher sets aside the world and the entirety of its content—including the researcher’s physical body . While dedication to this bracketing is challenging to maintain, Husserl asserts that it is necessary. Suspending reliance on and foundations in physical reality is the only way to abandon our human experiences in such a way as to find the transcendent I. Researchers might borrow  practices from other qualitative research methods to achieve this goal. For instance, a study could be designed to have multiple researchers triangulate  their reductions to confirm appropriate bracketing was maintained. Alternatively, a study could involve validation of data  via member checking  to ensure that the identified essences resonated with the participants’ experiences.
Husserl’s transcendental phenomenology has been employed by HPE researchers. For example, in 2012, Tavakol et al. studied medical students’ understanding of empathy by engaging in transcendental phenomenological research . The authors note that medial students’ loss of empathy as they transition from pre-clinical to clinical training is well documented in the medical literature , and has been found to negatively impact patients and the quality of healthcare provided . Tavakol et al.  used a descriptive phenomenological approach (i. e. using the methodology of Colaizzi and Giorgi) to report on the phenomenon of empathy as experienced by medical students during the course of their training. The authors identified two key factors impacting empathic ability: innate capacity for empathy and barriers to displaying empathy .