Symbolic knowledge evolved starting from the days that we lived in caves and ate raw meat. Humans must have started the spoken language by forming words for common things that they saw everyday. (mother, father, sky, trees) regardless of the cultures, people identified certain common concepts like ‘space’ and ‘time’. People started forming theories around various phenomena they experienced. These were the early sciences. The early sciences must have been to do with formulating theories regarding generating fire, hunting, gathering, cooking, curing ailments etc.
I am going to use the word ‘science’ in a slightly controversial way from this point onwards. Within different worldviews the word ‘science’ has many meanings. If you believe science originated in Western Europe, during the scientific revolution, following the period of enlightenment, then you may oppose my use of the word ‘science’ outside of that definition. If you believe that any system that is not based on conscious application of scientific method (i.e. trial and error) and methodology of objectivity is not a science, then you may oppose my use of the word. However, if you think that science is all about coming up with useful models, then you would agree with me.
In "මගේ ලෝකය", Nalin De Silva discusses three stages of science called primary, secondary and tertiary. The primary sciences are the knowledge systems each tribe created to fulfill their needs. These sciences were coupled very tightly with their cultures. One such scientific theory Sri Lankans had (and still have) goes like this: (This example is directly from the concepts from "මගේ ලෝකය") The theory was formulated to describe and cure certain illness occurring in young, and unmarried, women. When a young women is exposed to the demonic power of “Kalu Kumara Yaka” (a demon) they contract this mental illness. This is a kind of demonic possession. The symptoms are - bursting into violent, hysterical attacks, loss of consciousness, loss of appetite, etc. To cure this illness there is a procedure called “Thovilaya” (exorcism) where certain elaborate dances and offerings to the demons are conducted. Usually after this procedure the woman is cured. Above is a perfectly scientific model based on empirical observations. This is a proven theory, which can be used to improve the quality of life of humans. The mental ailments can be cured using this theory and its practice. However, today we have different theories and procedures to describe and cure mental illnesses. There is a separate field in medical science called psychiatry where we can describe and cure psychological illnesses with better success rate than the previous model ancient Sri Lankans used. However, this does not make the “Kalu Kumara Yaka” theory less scientific. It is just less accurate and less credible.
In science, we do not discard a model which can do useful work for us, even if we know that the model is inadequate in some specific situations. A good example may be the fact that NASA used Newtonian classical mechanics to calculate the trajectories for the first lunar mission, and not equations put forward by Einstein’s theory of relativity. In the case of moon landings, classical mechanics was adequate to calculate the trajectories of the space probes within the required accuracy. The classical theory of gravity suggests the existence of a hypothetical pulling force between masses. It also suggests the ‘action at a distance’ where this pulling force is ‘felt’ by the masses instantaneously at a distance. Einstein’s theory of relativity rejects both these concepts and it uses entirely different model to explain the motion of bodies through the space-time continuum. One who believes in an underlying reality may ask, “does gravity really exist?” From a logical positivist perspective the question has no meaning. Gravity is a model to explain why objects seem to fall towards Earth. It exists only in Newtonian classical theory of mechanics. Newtonian theory is a good scientific theory, though it cannot explain things like the peculiar trajectory of planet Mercury around the Sun.
 One may argue that it is not correct to call these kinds of theories ‘scientific’ according to the usual philosophy of science. True that I am using the term considering the epistemological implications only, which is not the common usage of the word ‘scientific’
 Note that modern scientific concepts like ‘black hole’, ‘string’, ‘p-brane’, ‘quark’ are not any more tangible than hypothetical ‘Kalu Kumara Yaka’.