From the perspective of the west, it all began in ancient Greece, around 600 BC. This is during the Axial Age, a somewhat controversial term coined by the German philosopher Karl Jaspers to denote the remarkable intellectual and spiritual awakening that took place in various places around the world in the space of a century. Apart from the Greek explosion of thought, it is the time of Siddhartha Gautama (or the Buddha) in India, of Confucius and Lao Tzu in China, of Zoroaster (or Zarathustra) in ancient Persia – religious leaders and thinkers who would have the meaning reformulate faith and morality. In Greece, Thales of Miletus and Pythagoras of Samos were pioneers in pre-Socratic philosophy, shifting the focus of inquiry and explanation from the divine to the natural.
The divine never completely abandoned early Greek thought, but with the advent of philosophy, trying to understand the workings of nature through logical reasoning, unlike supernatural reasoning, would become an option that did not exist before. . The history of science, from its early days to the present, can be told as an increasingly successful split between belief in a supernatural component to reality and a strictly materialistic cosmos. The Enlightenment of the 17th and 18th centuries, the Century of Reason, literally means ‘to see the light’, as the light here is clearly the superiority of human logic over any kind of supernatural or unscientific methodology to the “truth” of things.
Einstein was a believer for the first time and preached the fundamental reasonableness of nature; no strange inexplicable things, like a god playing dice – his tongue-in-cheek critique of the belief that the unpredictability of the quantum world was truly fundamental to nature and not just a shortcoming of our current understanding .
To what extent we can understand the workings of nature through logic alone, science cannot answer. This is where the complication begins. Can the human mind, through the diligent application of scientific methodology and the use of increasingly powerful instruments, achieve a complete understanding of the natural world? Is there an ‘end to science’? This is the sensitive issue. If the rift that began in pre-Socratic Greece were to be completed, nature as a whole would be fit for a logical description, the complete set of behaviors that scientific studies have identified, classified, and described through eternal laws of nature. All scientists and engineers need to do is put into practice this knowledge, inventions and technologies that meet our needs in different ways.
This kind of vision – or hope, really – goes back at least to Plato who in turn owes much of this expectation to Pythagoras and Parmenides, the philosopher of Being. The difference between the primacy of that which is timeless or unchangeable (Being), and that which is changeable and fluid (Word), is at least as old. Plato suggested that the truth was in the unchanging, rational world of Perfect Forms that preceded the bothersome and deceptive reality of the senses. For example the abstract form Chairman contains all chairs, objects that can take many forms in our sensory reality while serving their functionality (an object to sit on) and basic design (with a seating area and a few legs underneath). According to Plato, the forms hold the key to the essence of all things.
Plato used the allegory of the cave to explain that what people see and experience is not the true reality.
Credit: Gothika via Wikimedia Commons CC 4.0
When scientists and mathematicians use the term Platonic worldview, it is what they generally mean: the unbounded ability of reason to unlock the secrets of creation one by one. Einstein was a believer for the first time and preached the fundamental reasonableness of nature; no strange inexplicable things, like a god playing dice – his tongue-in-cheek critique of the belief that the unpredictability of the quantum world was truly fundamental to nature and not just a shortcoming of our current understanding . Despite his strong belief in such an underlying order, Einstein acknowledged the imperfection of human knowledge: ‘What I see of nature is a beautiful structure that we can only understand very imperfectly and that must fill a thinking person with a sense of humility. ‘ (Quoted by Dukas and Hoffmann in Albert Einstein, The Human Side: Glimpses from His Archives (1979), 39.) Einstein embodies the tension between these two conflicting worldviews, a tension that is still very much with us today: On the one hand , the Platonic ideology that the fundamental things of reality are logical and comprehensible to the human mind, and, on the other hand, the recognition that our reasoning has limitations, that our instruments have limitations and thus to a kind of final or complete understanding to reach the material world is nothing but an impossible, semi-religious dream.
This kind of tension is palpable today when we see groups of scientists passionately advocating for or against the existence of the multiverse, an idea that says our universe is one in a large number of other universes; or for or against the final unification of the laws of physics.
Of course, nature is always the final arbiter of any scientific dispute. Data decides somehow. It is the beauty and power that is at the heart of science. The challenge, however, is to know when to abandon an idea. How long must one wait until an idea, seductive as it may be, is considered unrealistic? This is where the debate becomes interesting. Data to support more “out there” ideas, such as the multiverse or extra symmetries of nature required for unification models, refuse to appear for decades, despite extensive searches using various tools and techniques. On the other hand, we only find when we look. So should we continue to defend these ideas? Who decides? Is it a community decision or should everyone follow their own way of thinking?
In 2019, I am participating in an interesting live debate at the World Science Festival with physicists Michael Dine and Andrew Strominger and presented by physicist Brian Greene. The theme was string theory, our best candidate for a final theory on how the particles of matter interact. When I completed my doctorate in 1986, string theory was the manner. The only way. But by 2019, things have changed, and very dramatically, due to the lack of supporting data. To my surprise, both Mike and Andy were completely open to the fact that the certainty of the past was no more. String theory taught physicists many things, and it was perhaps its use. The Platonic prospects were in jeopardy.
The dispute remains alive, though the dream with each experiment that does not show evidence for string theory becomes more difficult to justify. Will it be a generational thing, as the celebrated physicist Max Planck once said: “Ideas do not die, physicists do not?” (I paraphrase.) I hope not. But this is a conversation that needs to take place more in public, as was the case with the World Science Festival. Dreams die hard. But they can die a little easier if we accept that our understanding of reality is limited and does not always meet our expectations of what may or may not be.