Science derives from the Latin word scientia, meaning knowledge. In the strictest sense, science can only be one subject-knowledge. While it is possible to make general divisions in science, these divisions can never be strict. At first sight, botany and zoology appear to be distinct enough. The first concerns plants, while the second animals. But there are some creatures that are neither animal nor plant-or at least scientists have not yet been able to decide the issue. While plantlike corals are made to fit uneasily into the animal kingdom, fungus remains excluded from both. During the first stages of its life the chamaeleon is animal-like, swiftly moving across the seas with its cilia. Yet, after having consumed its fill it turns into a plant, fixed to the sea bed and using chlorophyll to produce its food (characteristic of plants). These oddballs find summary mention in both textbooks.
And this is only the beginning. Biochemistry gatecrashes into both fields mentioned above, involving life at the level of the molecules, where it is clearly chemistry. Ecology invites all three to an ice-breaking party, to see in what way they all work together to form an intricate complex. Also invited are geology and meteorology, sponsors of the whole thing. Human geography has been goaded to come along, treated with caution because this one can upset the whole thing. And once we have brought human behavior into the fray, we have flung the door open all the social sciences.
What about the fact that the social sciences tug along all the humanities in their wake? This is where the security forces make their entrance. Science is confident that it has its own special method of arriving at knowledge. It takes empirical data, measures them with highly accurate instruments and uses induction and deduction to arrive at well-defined theories. There is nothing wishy-washy like belief and imagination here. What are got are hard facts, straight from the horse’s mouth-or nature's mouth. The humanities, with their imaginative talk and flowery opinions, are not allowed into the citadel of science. That's one point that science can be domineering about. The security people at the gates are very harsh toward the humanities.
At least they were at first. But over time all the humanities have been able to hoodwink the guards, and are now sitting comfortably inside the citadel. They realized that they only needed a change of wardrobe. They only had to put their work into a certain structure–start with premise, list assumptions, carry out analysis, arrive at conclusion; techniques are defined, categories are numbered. With such a sartorial makeover, they were given a new distinction-more social sciences.
Science didn't want to branch out; it only became necessary. To the ancient Greeks, everything was philosophy. Aristotle talks about plant classification as well as about the nature of the soul, and calls both philosophy. Things only began to get out of hand since the Renaissance. Roger Bacon in the 13th century was the first to advise scholars to leave their ivory towers and dirty their hands. This "dirty hands" approach to obtaining knowledge is what eventually became known as science. Francis Bacon set up the rules clearly, in the 17th century. By this time it had acquired a name-natural philosophy. It was the poor relation to proper philosophy. (What was studied by the latter day today comes under the heading of the philosophy of religion.)
The Oxford Dictionary records that the word “science” was first applied by William Whewell in 1834. By this time a few divisions had sprung up. Robert Boyle called himself "The Sceptical Chymist" in a book of the same name published in 1661. He only wanted to distinguish his study from alchemy (a pseudoscience, and never allowed into the fold). If asked, he would not have been able to explain the difference between chemistry and what Galileo was doing by rolling balls down an inclined plane. Separation of science into separate fields was the plan of nobody. It gradually caught up with scientists unawares. It really began to explode in the latter half of the 19th century, and it was the sorry task of the textbook writers, the professors in their academic surrounds, to define the limits of each subject.
When Alfred Nobel introduced his landmark prizes in 1901, he thought that physics, chemistry and medicine were clear enough distinctions. But over the years the judges in Stockholm have struggled to ascertain which category any particular research should fall into. So Marie Curie got one of her prizes in physics and the other in chemistry. You cannot blame them. Where do you put radioactivity? Atomic physicists explain it, while the chemists observe it as properties of certain elements.
The fudge between subjects only increases as science advances. New fields emerge because the fudge becomes too embarrassing, or because there are so many people working inside the fudge that they start to feel homeless, and want a new home. Those geologists who have no time for rock collection, and are spending all their time working out the physics of plate tectonics, set up camp under the new flag of geophysics. Paleontologists who study only dinosaurs prefer the term neuroanthropology… no, It’s better not to ask what that studies.
In his 1959 Rede Lecture entitled “The Two Cultures,” C. P. Snow mourns the unmendable breach between the sciences and the humanities. He felt that scientists and the practitioners of the humanities could no longer talk to each other. Being distinguished in both fields (he had distinguished himself in science before turning novelist), he knew that truth lies in both, and one could not be said to be knowledgeable if accomplished in one and ignorant in the other. Of course, he was only reviving the Greek view of knowledge-as a single body, philosophy.
C. P. Snow does not seem to have appreciated the situation fully. Let alone scientists talking to litterateurs, scientists cannot even speak among themselves any more. Put a pharmacologist and an astrophysicist in the same room and they would be practically foreign to each other. And it wouldn't even help to point out to them that some pharmacological substances had been found in stars. Some among them might get so interested in the subject that they start devoting all their time to it, and then there is a new subject, say, pharmo-astrophysics.