In the beginning, there was man. As man developed, so did his curiosity about the natural world around him. Humans sought to explain all naturally occurring phenomenon through experimentation and observation. The first worldly scientists called themselves natural philosophers. This, I feel was a much more accurate description. Their theories, though vague and obscure at first, have been redefined through the years to form what we know today as being law. Among these unrefined theories were the basic views on agriculture (this was considered the most important science, since it freed the people from survival to exploration), basic human physiology and alchemy. We now know more of these subjects than can ever be learned in one man's lifetime, all because of documentation and study of intelligence throughout the ages.
I have always understood science to work as follows: in order to know everything about something, you have to know everything. For you to know everything about plants, you need also to know about solar and lunar rotation, atomic structures and integrity against external forces like wind etc. along with thermo dynamics and oxidation and reduction reactions to know how photosynthesis works. All of these things (and a lot more) form a part of every plant's everyday life. It is, therefore, important to know that while some things can simply be explained for understanding, those things will never be completely understood. It is therefore known that all things are interconnected and, thusly, it forms part of every scientists dream to create a unified theory on life, the universe and everything. This was exactly the goal that the earliest natural philosophers set out to achieve.
One day, if all goes well and no knowledge is kept from the thinking public, such a unified theory will come into existence. When this happens science as a description for natural phenomena will die. There will be no need to experiment. There will be no need to observe. All that will be left is to pass on this knowledge to the next generation and the next after that, as it has been done throughout history. Science will have given itself reason to not exist as anything more than a reference in history books. The origin of the greatest struggle for knowledge that lasted thousands of years. The only question we have to ask ourselves if such absolute knowledge ever comes into existence is this: what next?