IB May 2026 (M26) TOK Title #2 Model Response
To what extent do you agree that doubt is central to the pursuit of knowledge? Answer with reference to two areas of knowledge.
- The essay below is written as a teaching draft to illustrate the structure, tone, and depth of analysis expected in a high-scoring Theory of Knowledge essay.
- It includes call-outs after each paragraph that explain why particular choices were made and how they align with the IB assessment criteria.
- In a formal submission, you would need to provide proper references and citations (using MLA, APA, or the referencing style your school/IB requires).
Introduction
Doubt is the signal that what we currently believe might be incomplete or wrong. “Central” means more than merely present. It means that doubt coordinates and drives the process across contexts. I agree to a considerable extent that doubt is central to the pursuit of knowledge, especially in the natural sciences and the human sciences. In the natural sciences, structured skepticism turns anomalies into discoveries. In the human sciences, methodological doubt reshapes how claims are tested and trusted.
Yet doubt is not universally central. At times, other drivers such as measurement capacity, community norms, or available methods are the real bottlenecks. My claim is a graded one. Doubt is central often, but not always. It is most central when anomalies reveal live uncertainty and when a field possesses tools to convert doubt into disciplined inquiry.
- Purposeful definition of “central”
- Explicit stance using “to a considerable extent”
- And a preview of condition which frames the paper as an evaluation, not description.
Natural Sciences I: When Doubt Triggers Decisive Tests
In medicine, peptic ulcers were long attributed to stress and diet. Barry Marshall and Robin Warren doubted this consensus after observing spiral bacteria in gastric biopsies. Their skepticism generated a testable hypothesis about Helicobacter pylori, which was confirmed through clinical trials. This overturned standard treatment and earned a Nobel Prize. Here, doubt is central because it initiated the research programme.
Without doubting the stress model, the same instruments and methods would not have been deployed in this direction. The pursuit advanced because doubt redirected attention toward a hidden causal mechanism.
- The paragraph begins with the old consensus because TOK paragraphs work best when you set up the “knowledge claim” first.
- The story is kept brief to avoid drifting into history-of-science writing, with the final two sentences circling back to the title.
- Every body paragraph should have this explicit return so examiners can see the link.
Natural Sciences II: Anomaly-Driven Doubt Reshaping Theory
In particle physics, the solar neutrino problem persisted for decades. Detectors consistently found fewer electron neutrinos than predicted by solar models. This anomaly created sustained doubt in both astrophysics and detector design. The scientific response was to build new detectors sensitive to different neutrino types and test whether neutrinos change identity in flight.
The eventual confirmation of neutrino oscillations revised the Standard Model and solved the deficit. Here doubt is central because it coordinated theory, method, and apparatus. Knowledge grew by treating doubt as a signal that current explanations were insufficient.
- This example broadens the scope of the science discussion by moving from medicine to physics shows range.
- The word “anomaly” is deliberate, because in science anomalies are the clearest way to show doubt has force.
- The paragraph ends with “coordinated theory, method, and apparatus” to stress centrality.
- Examiners want to see that doubt doesn’t just exist in the background, but actively ties parts of the discipline together.
Natural Sciences III: When Doubt Isn't Central
There are also contexts where doubt is present but not the bottleneck. In school chemistry labs, we already doubt whether titration readings are exact, but what constrains knowledge is the instrument’s resolution. A burette with 0.1 ml markings cannot measure beyond its design.
Similarly, before the Hubble Space Telescope, astronomers doubted their blurred images, but the true advance came when sharper instruments became available. In these cases, I agree to a limited extent that doubt is central. Knowledge advanced when capacity improved, not because skepticism deepened.
- This paragraph serves as a counterbalance.
- The school titration example makes the idea accessible and relevant to you while Hubble adds weight as a professional science case.
- Pairing the two stops the point feeling shallow.
- The phrase “limited extent” is intentional; graded language needs to appear often for examiners to see that you're answering the exact command term.
Human Sciences I: Doubt That Reforms Entire Methods
In psychology, the Registered Replication Reports on ego depletion created sustained doubt about a once-popular effect. Large, multi-lab studies failed to reproduce earlier findings. This doubt forced reforms such as pre-registration, open data, and stricter analysis plans.
The pursuit of knowledge improved not through new theories, but through institutional redesign. Doubt was central because it redefined what counted as acceptable evidence. Without that collective skepticism, psychology would have continued to reward fragile results, slowing cumulative progress.
This shows how doubt acts on the rules of method, not just single claims.
Human Sciences II: When Doubt Isn't Central To Progress
There are times when practical constraints matter more than doubt. Take standardized exams such as the IB Physics Paper 2. Students may doubt their answers, but what determines performance is often mastery of calculation techniques, time management, and familiarity with past paper styles. Doubt about an answer rarely drives deeper knowledge in that moment; the bottleneck is procedural skill and preparation.
Similarly, in large projects like the IB Extended Essay, progress often stalls not because of doubt about the topic itself, but because of practical factors such as procrastination, time management, or access to sources. A student may doubt the quality of their research question, but what actually slows progress is usually delaying drafts or struggling to organize work. In this context, doubt still exists, but it does not coordinate the pursuit. What matters more are habits and resources that allow steady progress. Knowledge advances when these practical barriers are overcome, not when more skepticism is applied.
Human Sciences III: When Doubt Derails Inquiry
There are also contexts where doubt becomes counterproductive. In public health, selective doubt about vaccines has been amplified by misinformation campaigns. This doubt does not generate better knowledge. Instead, it immobilizes policy and undermines trust in evidence. In such cases, the central driver of knowledge is not more skepticism but stronger institutions, transparent communication, and trust networks.
For policy-adjacent areas of the human sciences, I agree to a moderate extent that doubt is central. Progress depends on channeling skepticism productively rather than letting it dominate.
This shows recognition of the costs of doubt.
Conclusion
I agree to a considerable extent that doubt is central to the pursuit of knowledge. In the natural sciences, doubt converts anomalies into discoveries and prevents stagnation. In the human sciences, structured doubt reforms methods and sharpens validity. Yet doubt is not the only driver. Where measurement, access, or trust are the bottlenecks, doubt is present but not coordinating.
The lesson is that doubt is most central when systems are designed to convert it into tests and revisions. If we want knowledge to flourish, we must treat doubt as a resource, not as a threat, and build communities that can use it well.
Direct answer with “considerable extent,” conditions restated, and a practical takeaway.
