The Three Types of Science: Experimental, Inferential, Fantasy6 min read

Kirk Durston has written a fine suite of articles on the three types of science, and has done a short set of corresponding podcasts on them on the ID The Future podcast. Unfortunately, neither has summarized the definitions in one place, so you’re welcome. Links to to the various sources below. ^{1 2 3 4 5 6}

1. Experimental Science (the present)

Experimental science involves directly testing hypotheses through controlled, repeatable experiments to observe cause-and-effect relationships. This type of science is unique in that it is reproducible and verifiable. If it can’t be observed and reproduced in experiment, it is not experimental, a.k.a. empirical science.

Examples:

1. Physics: Testing Newton’s laws by observing objects in controlled environments.
2. Biology: Investigating bacterial growth under varying conditions.
3. Chemistry: Analyzing reaction rates by altering temperature or pressure.

Interestingly, much of modern experimental science has a real problem with reproducibility, in that less than half of all peer reviewed science is reproducible. ^{7 8 9}

2. Inferential Historical Science (the past)

Inferential historical science studies events and processes in the past that cannot be directly observed or repeated. It relies on interpreting evidence and making logical inferences to reconstruct what likely occurred. We use the historical artifacts we have, and our current knowledge of natural processes which we assume were in effect in the past, and we use abduction, that is, inference to the best explanation.

Examples:

1. Paleontology: Reconstructing dinosaur diets or behaviors from fossilized remains.
2. Geology: Understanding plate tectonics and mountain formation based on stratigraphy.
3. Astronomy: Inferring the Big Bang and galaxy formation using light from distant stars.
4. Evolutionary Biology: Interpreting the fossil record, genetic similarities, and phylogenetics to infer the evolutionary history of species.
   • Example: Using DNA to trace the common ancestry of humans and primates.
5. Origins Science: Studying the origin of life and the Earth’s early history through chemical and geological evidence.
   • Example: Investigating the conditions of Earth’s primordial environment to infer how life began.

By categorizing evolutionary biology and origins science under inferential historical science, we highlight their reliance on indirect evidence like fossils, molecular biology, and radiometric dating to infer processes and events that shaped life and Earth’s history. These fields are distinct from experimental science because they cannot observe past events directly, but they provide robust frameworks for understanding the past through evidence-based reasoning.

3. Fantasy Science (the future)

Fantasy science explores imaginative and speculative ideas that often disregard empirical evidence or natural laws. It resides in the realm of fiction but can inspire creative thinking and innovation. While it is often used in speculation about future science by extrapolating current ideas, it can also be extended to the past to imagine how mythical creatures or legendary societies accomplished unusual tasks.

Examples:

1. Time Travel: Imagining scenarios where individuals travel to the past or future.
   • Example: Speculating on paradoxes like altering history.
2. Interdimensional Universes: Theorizing about parallel realities with different physical laws.
   • Example: Fictional settings where gravity or time functions differently.
3. Technological Speculation: Proposing advanced or magical technologies.
   • Example: Faster-than-light travel or teleportation.
4. Dragons: Proposing supposed methods for fire generation in the throats of dragons.
5. Human Evolution Speculation: Imagining impossible adaptations.
   • Example: Predicting humans developing telepathy or wings.

---

Key Differences Among the Three Types

Feature	Experimental Science	Inferential Historical Science	Fantasy Science
Based on Evidence	Yes	Yes (but indirect and interpretive)	No
Testable/Repeatable	Yes	No (focused on past, unique events)	No
Adheres to Natural Laws	Yes	Yes	Often no
Purpose	Understanding present processes	Reconstructing the past	Imagination and speculative inquiry
Examples	Drug trials, chemical reactions	Fossil studies, evolutionary biology, geology	Time travel, multiverses, warp drives

Conclusion

It is crucial to avoid the assumption that “science has proven” something with absolute certainty. This is especially true for inferential science, which deals with events of the past, such as the origins of the universe or life. Unlike experimental science, inferential science relies on abductive reasoning, which involves selecting the most probable explanation based on available evidence. However, the probabilities assigned to these explanations are themselves contingent upon the validity of the underlying assumptions.

Take radiometric dating as an example. This method, often used to determine the age of materials, relies on several critical assumptions. If these assumptions are inaccurate, the conclusions drawn may also be called into question. Some key assumptions include:

1. Initial Conditions: The original amounts or ratios of parent and daughter isotopes are accurately known.
2. Isolation of the System: The sample has not experienced leaching or loss of decay products over time.
3. No External Additions: There has been no introduction of additional isotopes to the system.
4. Decay Rate Consistency: The rate of radioactive decay has remained constant and unaffected by environmental or cosmic factors.

In certain cases, evidence has emerged that challenges one or more of these assumptions. For example, leaching of decay products has been observed under specific conditions, and there is ongoing research into whether decay rates can be influenced by factors such as solar activity. Thus, while radiometric dating—and inferential science more broadly—provides valuable insights, its conclusions should be held tentatively and remain open to revision as new data and better methodologies emerge.

This underscores the provisional nature of all scientific inquiry, reminding us that science seeks to refine our understanding rather than deliver absolute, unchanging truths.