Clinical reasoning depends not only on what healthcare professionals know, but on how they know it, how they interpret evidence and whether they recognise the limits of their own perception. A courtroom argument about psychedelics, the inaudible frequency of a dog whistle and Auguste Rodin’s The Thinker offer an unexpected way to explore epistemology in clinical practice.
For pharmacy students and foundation pharmacists preparing for the GPhC exam and the pharmacy registration exam, this matters. Safe practice is not simply about recalling facts. It requires critical thinking, evidence interpretation, clinical judgement and the ability to recognise when the available information may be incomplete.
What is epistemology in clinical practice?
Epistemology is the branch of philosophy concerned with the nature, origin, limits and justification of knowledge.
In clinical practice, epistemology asks a deceptively simple question:
How do we know what we know?
Every patient consultation is an epistemological exercise. A patient presents fragments of information:
- symptoms;
- timelines;
- medicines;
- beliefs;
- observations;
- test results;
- previous diagnoses; and
- lived experience.
The practitioner must decide what these fragments mean. That process is central to clinical reasoning in pharmacy. It influences differential diagnosis, medicines optimisation, prescribing decisions, safety-netting and referral. But before returning to pharmacy practice, consider psychedelics.
What do psychedelics teach us about knowledge and perception?
The word psychedelic derives from the Greek psychē, relating to mind or soul, and dēlos, meaning manifest or reveal. The term was coined by psychiatrist Humphry Osmond in 1957 during correspondence with Aldous Huxley.
Today, psychedelics are often associated with counterculture. Historically, however, substances such as LSD were investigated within mainstream clinical research. Researchers explored their potential use in areas including alcohol dependence and distress associated with serious illness.
The history is important because it illustrates a broader epistemological problem:
The phenomenon may remain, while the framework through which we interpret it changes.
Something can move from medicine to mythology, from laboratory to counterculture and, decades later, back into scientific investigation. Legal and philosophical arguments have also explored distinctions between hallucinogenic and psychedelic experience. These distinctions are contested and should not be presented as settled scientific fact. Yet the underlying question remains intellectually valuable:
Does altered perception merely create something that is not there, or can a change in perception expose aspects of experience that ordinary consciousness does not usually access?
For healthcare professionals, the significance lies not in accepting any particular answer. It lies in recognising the question. And that brings us to the dog whistle.
What does a dog whistle teach us about clinical uncertainty?
A dog can detect sound frequencies beyond the ordinary upper range of human hearing. The signal exists. The human observer simply cannot hear it unaided. This creates a powerful analogy for clinical practice and diagnostic reasoning:
Our inability to detect a signal does not necessarily prove that the signal is absent.
Consider a patient reporting fatigue, dizziness, pain, cognitive change or a subtle deterioration in function. The initial blood tests may appear reassuring. The observations may be within expected ranges. The presentation may not fit a familiar diagnostic pattern. The consultation may be brief. The clinician may therefore be tempted to conclude that nothing significant is happening. But is the signal absent? Or are we listening on the wrong frequency?
Every healthcare professional operates within a finite perceptual and cognitive range. We notice some cues and miss others. We ask some questions but fail to ask others. Our interpretation is influenced by experience, time pressure, previous diagnoses, pattern recognition and expectation.
For pharmacists, this is particularly relevant when undertaking medication reviews, responding to symptoms, identifying adverse drug reactions or assessing treatment failure. Sometimes the clinical signal is present.
We are simply not equipped to detect it using our current approach.
What does Rodin’s The Thinker teach us about critical thinking?
Now consider Auguste Rodin’s The Thinker. There he sits: brow furrowed, body compressed, muscles visibly engaged. Rodin did not depict thinking as passive reception. He rendered it as effort. As tension. Almost as physical labour. That image offers a useful challenge for pharmacy education.
If learning consists only of:
- watching another lecture;
- reading another study guide;
- highlighting another page;
- or repeatedly reviewing familiar notes;
are we genuinely thinking? Or are we simply receiving information?
Clinical reasoning should involve cognitive effort.
A learner working through a clinical scenario should ask:
- What is happening here?
- Which information is clinically relevant?
- What evidence supports my interpretation?
- What does not fit?
- What alternative explanation have I ignored?
- What information is missing?
- What would make me change my mind?
These questions are important for university study, foundation training, future prescribing practice and preparation for the GPhC exam.
They also explain the educational philosophy behind Chemistomorrow.
Why does Chemistomorrow use practice questions and clinical scenarios?
At Chemistomorrow, we believe that pharmacy learning should involve more than passive content consumption.
Our approach uses practice-based pharmacy questions, clinical scenarios and pharmacy calculation questions to encourage learners to retrieve, apply and test their knowledge. The aim is not to replace university education. It is to complement it.
University study provides the scientific, clinical and professional foundations of pharmacy practice. Chemistomorrow provides an additional space in which learners can ask:
Can I apply what I know when the answer is not immediately obvious?
That distinction matters. A learner may recognise a treatment recommendation when reading notes yet struggle to identify it within a complex patient scenario. A learner may understand a calculation method when reviewing a worked example yet struggle to select the correct method independently. A learner may know several adverse effects of a medicine yet fail to recognise one when it appears indirectly in a patient history.
Application exposes the gap between: “I have seen this before” and “I can use this knowledge.”
That gap is highly relevant to GPhC exam preparation, the pharmacy registration exam, foundation year development and real-world pharmacy practice.
What are rationalism and empiricism in clinical reasoning?
Two major philosophical traditions help explain how clinicians pursue knowledge.
Rationalism
Rationalism holds that knowledge can be developed through reason, logic and deduction.
In clinical practice, rationalism appears when we:
- apply pharmacological principles;
- interpret disease mechanisms;
- use treatment algorithms;
- assess causal relationships; and
- reason from established evidence to an individual patient.
For example, a pharmacist may use knowledge of renal elimination to reason that declining kidney function could increase exposure to a medicine.
Empiricism
Empiricism holds that knowledge is grounded in observation and experience.
In clinical practice, empiricism appears when we:
- listen to the patient;
- examine clinical findings;
- review blood results;
- observe treatment response;
- measure physiological parameters; and
- gather evidence from practice.
The patient says the medicine makes them dizzy. The blood pressure falls. The symptoms began after dose escalation. These observations matter. Clinical practice requires both rationalism and empiricism. Yet both have limitations.
What are the limitations of rationalism in healthcare?
A heavily rationalist practitioner may force an unfamiliar presentation into a familiar framework. The reasoning may appear internally logical. But what if the starting assumptions are wrong? What if the patient does not resemble the textbook case? What if the phenomenon is genuinely novel? What if an established diagnostic label is anchoring subsequent interpretation? Reason is essential. But reason can produce a confidently incorrect answer when it operates from flawed premises.
What are the limitations of empiricism in healthcare?
Empiricism also has limits because observation depends on what we are capable of detecting. The dog whistle returns. The signal may exist beyond the receiver’s range.
In healthcare, our “receiver” includes:
- our senses;
- our consultation skills;
- our diagnostic tests;
- our questions;
- our clinical experience; and
- the conceptual categories available to us.
If we do not ask about a symptom, we may never discover it. If a test lacks sensitivity, a negative result may falsely reassure us. If we dismiss a patient’s experience because it does not fit our expectations, clinically important information may be lost. The absence of detection is not always the detection of absence.
Why is Immanuel Kant relevant to clinical practice?
Immanuel Kant challenged simple accounts of knowledge based solely on reason or solely on sensory experience. His philosophy is far more sophisticated than a straightforward compromise between rationalism and empiricism, but it offers a valuable lens for clinical reasoning. Experience matters. Reason matters. But experience is interpreted through structures of thought.
The effective healthcare professional therefore:
observes;
reasons;
tests;
revises;
and remains willing to discover that the first interpretation was wrong. In that limited but useful sense, the effective practitioner is Kantian.
What questions should a reflective clinician ask?
A reflective pharmacist or healthcare professional should repeatedly ask:
Am I receiving the full clinical signal, or only the frequencies I am equipped to detect?
Am I reasoning carefully, or merely confirming what I already believe?
Does this patient genuinely fit the pattern, or am I forcing the patient into it?
What information is missing?
What evidence would make me change my mind?
These are not abstract philosophical exercises.
They are relevant to:
- safe prescribing;
- differential diagnosis;
- medication review;
- adverse drug reaction identification;
- medicines optimisation;
- clinical assessment;
- patient-centred consultation;
- safety-netting; and
- referral.
They are also relevant to pharmacy students and foundation pharmacists preparing for the GPhC exam.
Why does this matter for GPhC exam preparation?
Effective GPhC exam preparation requires more than memorising isolated facts.
Candidates need to interpret information, identify clinically relevant details, apply pharmaceutical knowledge and make safe decisions within patient-centred scenarios.
The same principle applies to pharmacy calculation questions. Knowing a formula is not always enough. The learner must identify:
- what is being asked;
- which information matters;
- which information is distracting;
- which method is appropriate; and
- whether the final answer is clinically plausible.
This is why repeated engagement with questions can be valuable. A good question does more than test whether you know the answer. It reveals how you think.
From exam preparation to future pharmacy practice
The purpose of enquiry should extend beyond passing the pharmacy registration exam. Foundation pharmacists are developing for increasingly complex clinical roles. They must learn to work with incomplete information, communicate uncertainty, recognise risk and make defensible decisions.
The patient will not arrive with a highlighted textbook chapter. The consultation will not tell you which clinical topic is being tested. The important clue may be subtle. The obvious diagnosis may be wrong. The first answer may need revision. That is why clinical learning should involve enquiry.
At Chemistomorrow, we believe learners should not only accumulate answers. They should practise interrogating the route by which an answer is reached.
Because the future pharmacist will work in environments where:
- information is incomplete;
- uncertainty is unavoidable;
- the patient does not follow the textbook;
- evidence requires interpretation; and
- the first explanation may be wrong.
The art of clinical practice lives in the disciplined tension between what we know, what we observe and what we may have failed to perceive. Approach the pursuit of truth with curiosity. Use reason. Respect evidence. Question your instruments. Interrogate your assumptions.
And remember that between what exists and what we perceive, there is frequently a gap. In that gap, the most important clinical truths may be quietly waiting.
The Thinker is not at rest. Neither should we be.