In the 1300’s a plague known as “The Black Death” swept through Europe, killing over 25 million people. The terrified population, fearing what they perceived as some well deserved punishment from God, were unable to take actual measures to prevent the spread of the illness, as they were ignorant of its origin. If a time-traveler were able to visit Medieval Europe and explain to them that what they were experiencing was actually disease caused by tiny entities, too small to see with the human eye, that were regurgitated into their bodies by fleas or carried on droplets of mist, also too small to see, this traveler would likely be regarded as a lunatic. This is where parsimony fails. Sometimes the simpler explanation, in this case that God is punishing people, is actually not the case. An invisible world of tiny germs would have seemed like ridiculous fantasy to those unable to see it. Nevertheless, it is true.
Science, and the modern scientific method are based upon empirical evidence. Empirical evidence is that which can be seen and observed through our senses. The problem with this is two-fold. For one, sometimes our senses deceive us.
When Johannes Kepler and Galileo Galilei tried to promote the Copernican heliocentric model of the solar system, it was roundly rejected. Considered a heretic for his views, Galilei would spend the remaining nine years of his life under house arrest. It was quite easy to convince the population of the time that promotion of this theory amounted to the ravings of madmen, or worse, evil men. Did the sun not rise and set in an arc across the sky? One’s own eyes would seem to prove that the sun was revolving around the earth as one stood firmly still upon it.
The second problem with empiricism is that it is based upon senses that cannot capture the entirety of reality. Humans possess three types of visual cones that allow them a particular range of color. Certain types of birds, fish, and insects possess four, meaning that they can see ultraviolet light, and have the ability to distinguish patterns that humans cannot. A dog will start howling at an emergency siren before a human even hears it, as there are waves of sound that cannot be detected by the human ear. Just because a human cannot perceive a particular reality through the senses does not mean that that reality does not exist. If an actual sixth sense existed, human beings could not conceptualize it, in the same way that a person who has never had sight cannot conceptualize sight.
René Descartes realized the fallibility of the senses, drawing much ridicule from the British empiricists of the time. He argued that the senses alone are not enough to discover truth, and that empirical information must be accompanied by the application of pure reason. By observing the properties of a ball of wax in a solid state versus a liquid state, he attempted to demonstrate that the knowledge derived purely through observation by the senses is inferior to the knowledge obtained by combining observation with logical thought.
Of course, the inability to sense something does not always have to remain so. The development of technology can enlarge the capabilities of human senses. It is now clear that those tiny entities, invisible to the naked eye, are what cause diseases such as the plague, because they can now be detected when previously they could not. Technology has allowed ideas to be proven by the requirements of the scientific method, but before those facts were proven they were mere concepts in someone’s mind that proposed a manner of looking at things outside of the mainstream way of thinking. These concepts often brought ridicule, not to mention actual danger, to the person that dared to think and articulate them.
One cannot see the size and shape of the forest when one is in it, but can more accurately gauge its nature if the contents and boundaries are explored and those observations are connected together in patterns in one’s mind. One can even more effectively determine the nature of a forest if one has an aerial photograph. In this way, senses, logic, and technology come together to provide a more accurate representation of reality.
Keeping in mind the limits of our senses as well as the historical lessons regarding scientific thought, one might consider what the future will look like and consider what assumptions there are about the world right now that may be found to be erroneous down the road. One might also consider that theories and speculations that are now thought to be wild and pseudo-scientific because they cannot be proven, could prove to be absolutely correct. One could argue that a wise position to take in regards to these matters would be one of both skepticism and open-mindedness—that absolute truth cannot be known, only sought after.