Lesson 4: The Origin of Knowledge 4.1 The Rise of Science There are, we have argued, three sources of knowledge. The first is the kind of knowledge deriving from our expectations as a living organism, largely pre-programmed and modified by experience admitted through our particular senses. The second is tradition - what we are told by our parents and by our culture. The third is based on scientific observation, that is, observation that follows rules which are acceptable to people trained in logic and math. (And to people with a lot of common sense and no stake in the results - hence the old saw "Out of the mouths of babes..." and the parable of the Emperor's New Clothes.) To increase understanding - to make better models of the world which can explain many more of the things that puzzle us - scientists make systematic observations. And since our knowledge is based primarily on vision, science took off in earnest when our means of extending our vision increased, first by travel around the Earth, and then by instruments allowing us to see the invisible. It all started to happen around AD 1600, following the discovery that Earth is round, and that Europe and the Mediterranean regions (medi-terranean = "in the middle of the world") are but a small part of it. Clearly, there were things the ancient philosophers had not told us! Could it be that they did not know everything? Could it be that many things remain to be discovered? These kinds of questions brought the Renaissance into being, a time when the learned became scientists. Telescopes showed us that the Moon is a planet like Earth, with plains and mountains, and that Jupiter is a solar system in miniature. When Galileo (1564-1642) looked at the Moon through his telescope some 400 years ago, it ceased to be an object of adoration and became an object for scientific study. Microscopy brought into view bacteria and other microbes and taught us about the intricacies of sexual and asexual reproduction. When Anton van Leeuwenhoek (1632-1723) reported that standing water is teeming with life, with a million "animalcules" in a single drop, Life was never the same again. It took another two hundred years (!) to establish that these life forms follow the same rules as the visible ones - that is, "Life only comes from life". Louis Pasteur (1822-1895) did the experiments, first showing that fermentation of milk and of beer is done by different organisms, and then showing that there is no fouling of a broth, even in a flask open to air, if particles in the air are excluded from entering. There is no spontaneous generation of complex life forms on the present day Earth. The evolution of far simpler molecular life occured in conditons that no longer exist here. What we now think of as "prescientific" beliefs were not necessarily based on lack of observation. The full Moon does influence sleep patterns of many people, and hence their mood. The Moon, therefore, could be endowed in the public mind with certain powers. The Moon certainly plays an important part in the reproductive cycle of many organisms. Concerning "spontaneous generation", it is a fact that maggots arise in rotting meat. Early observers may be excused for missing the laying of eggs by flies, eggs so small they are practically invisible. Put a fine net over the meat: it still rots, but no maggots. Doing science is to find a way to agree on what is happening in the world, and how the world works, or how it is put together, independently of whether the scientists are from one culture or another. Where it gets interesting is where the results from such common-sense investigation conflict with older ideas as to how the world was made, or works, or where we come from. From ancient times, beliefs preceded knowledge, and beliefs are important in guiding our actions. Thus, beliefs are resistant to change, with good reason. The celebrated story of how Galileo was put under house arrest (for saying that scientific observation is preferable to the say-so of cardinals) is but one example illustrating the conflict. It goes on even today when school boards discuss the merits of evolution. Science is a way to generate conflict and to deal with conflict, not a way to avoid it.