Intuition and common sense are essential and fallible

Question assumptions and empirically test ideas

"It doesn’t matter how beautiful your theory is or how smart you are. If it doesn’t agree with experiment, it’s wrong."— Richard Feynman

Intuition, common sense, and imagination are advanced forms of thinking and essential aspects of human intelligence. Albert Einstein said imagination was more important than knowledge. As a cognitive scientist and philosopher, I rely on intuition and common sense. Common sense has differentiated humans from computers.

However, these traits can mislead. Intuition is inherently subjective, shaped by personal experiences, emotions, expectations, and unconscious biases, making it susceptible to blind spots and errors. Even human logic has limitations, often resting on unprovable axioms.

Additionally, our human-centric view limits our understanding of the broader realities of physical nature. Complex systems and the natural world require empirical data for accurate comprehension. Intuition, common sense, and even logic can fall short in fields such as nuclear physics, cosmology, biology, computer science, and medicine. Science has revealed many aspects of reality that defy human intuition and common sense.

The following are twelve examples:

1. The Shape and Motion of Earth: Earth appears flat from the ground, and the Sun seems to revolve around it. Yet, Earth is round, and the planets orbit the Sun. This understanding comes from scientific discovery, not our intuition or common sense alone.

2. Wave-Particle Duality of Light: Light exhibits properties of both waves and particles. It can spread out like a wave or behave like a particle in discrete packets (photons). This is seemingly illogical but tests have shown this to be true.

3. Density of Ice: Intuitively, solids should be denser than liquids, but ice floats on water because it is less dense.

4. Objects Falling at the Same Rate: In a vacuum, a feather and a hammer fall at the same rate, despite their different weights, contradicting the intuitive idea that heavier objects fall faster.

5. Hot Water Freezes Faster Than Cold: Counterintuitively, under certain conditions, hot water can freeze faster than cold.

6. Human Blind Spots: Each eye has a blind spot where the optic nerve connects to the retina, but our brain fills in the missing information, making us unaware of it in daily life.

7. Bananas Are Berries, Strawberries Are Not: Botanically, bananas are classified as berries because they develop from a single ovary with seeds embedded in the flesh. Strawberries, however, are aggregate fruits, forming from multiple ovaries.

8. Earth’s Proximity to the Sun in Winter: In the Northern Hemisphere, Earth is closest to the Sun in early January, during winter. Seasons are caused by Earth’s axial tilt, not its distance from the Sun.

9. Mount Everest’s Height: Measured from base to summit, Mauna Kea in Hawaii is taller than Mount Everest. Everest is the highest mountain above sea level, but Mauna Kea is taller when measured from its underwater base.

10. Probability and Coin Flips: Flipping a coin 10 times and getting heads each time doesn’t alter the 50% probability of heads on the next flip. Each flip is independent, challenging the expectation of "evening out" over the short term.

11. Underestimation of Exponential Growth: People often think linearly rather than exponentially, underestimating how quickly quantities grow in processes involving exponential growth, such as compound interest or population growth.

12. Water-Filled Bottle Trick: A water-filled bottle with a hole at the bottom won't leak if the cap is on tightly because no air can replace the exiting water, defying the expectation that any opening should cause leakage.

13. Visual Illusions: These demonstrate that what we see can defy our intuition and common sense.

    

    squares A and B are the same tone

    

    The two horizontal lines are straight and parallel

Balancing intuition and common sense with healthy skepticism and empirical testing is crucial to minimizing errors and expanding knowledge. Political and social policies, such as those on crime and health, must be data-driven not ideologically-driven to be effective.

This is why postmodernist skepticism of objectivity and empirical evidence poses significant risks to society and the world. Postmodernism theories are illuminating in the abstract. However, when applied to the real world, it undermines scientific consensus and evidence-based decision-making, potentially leading to harmful outcomes in public health, climate policy, and medicine. This skepticism promotes misinformation, superstition, and pseudoscience, erodes trust in institutions, and fosters political polarization and relativism. By prioritizing ivory tower ideology over factual data, it complicates effective governance and constructive debate.

Maarten Boudry, a Ghent University (Belgium) philosopher of science and well-known skeptic of pseudoscience, does not believe most academics really believe in postmodernism. He argues that they may believe in it in the abstract, but not when applied to specific facts of the real world. He thinks many academics who publicly say they agree that, for example, there are “different ways of knowing,” are being performative to fit in with prevailing politically correct social justice notions. He explains this in the below clip from a lengthy discussion titled “The Ideological Subversion of Science.”