How Do We Know What We Know (1)?

This is another topic that has occupied the attention of philosophers, linguists, mathematicians, scientists, and theologians for centuries. Assessing what we know is usually a tricky and ultimately (of course) a self-referential activity. Quantifying our own knowledge is difficult—what would we compare it against? Also, there is a natural human tendency to over-estimate how much we do know and under-estimate how much we don’t know. In addition to incorrectly estimating our quantity of knowledge, we typically overrate the quality or correctness of our knowledge in any domain in which we have experience and, indeed, in domains where we are not expert at all.

This is a topic I will revisit.

Resisting Knowledge

In his seminal book The Structure of Scientific Revolutions Thomas Kuhn noted that, far from boldly inventing new technologies and enthusiastically embracing change, scientists often strongly resist viewpoints, theories, and even clear evidence that contradict their established beliefs.

One of the greatest scientists of the closing days of classical Newtonian physics was William Thomson, more commonly known by his title of Lord Kelvin. He was a brilliant man, responsible for many scientific advances in the mid 19^th century especially in thermodynamics. But even this brilliant man had great difficulty accepting evidence that contradicted the beliefs he had so carefully constructed throughout his career. He died in 1907 passionately disputing the scientific advances in relativity and quantum mechanics heralded by Albert Einstein, Albert Michelson, Max Planck and others.

Lord Kelvin’s reaction to changes in his field was, according to Kuhn, quite common. Scientists, having built up strong arguments and models for their theories supported by their experimental evidence, cling to their models with great persistence often ignoring or discounting evidence that contradicts these models.

Apart from their obvious vested interest in their own work, there is another reason why scientists so vigorously defend their views...

...it is how they think.