Rather than ask how are science and philosophy different from each other, a better question would be, for purposes of the study of language, do philosophy and science use language differently than our everyday, normal use of language; and if so how? PARR
Split or LumpEdit
Both philosophy and science are so diverse that it is hard to find any rule that would allow us to cleanly distinguish between all of philosophy and all of science. Some philosophical traditions adopted the idea that there should be a subset of language that can be used like a form of mathematics to turn out truths. Some sciences have been heavily influenced by mathematics. Some physicists and computer scientists seem to think that the nature of physical reality and the nature of thought can be revealed by grinding out proofs of theorems and working within formal systems. An important part of modern science sprang from the conviction that we should not trust logic and reasoning alone to reveal the nature of reality. We need to get our hands dirty and open our eyes and explore the world we live in order to understand it. Time and time again, the paths we have been down when following logic have turned out to diverge from the nature of reality. Some philosophers and scientists want language to be like a laser beam that we can use to carve a beautiful statue of Truth. Other philosophers and scientists see language as a glowing bulb that can illuminate the dark and let us work our way into the unknown. However, the lamp of language casts shadows that can hide dangerous pitfalls.
Can we identify and clearly describe "our everyday, normal use of language"? Language can be thought of as an element of human cultural (note: I say this as someone who thinks that we do have a "language instinct", but there is no point in ignoring the cultural construction of functioning human languages). Some non-human animals have simple cultural elements. For example, some tribes of primates pass on certain patterns of behavior from generation to generation. If you study the use of such cultural elements, you find that they are closely linked to real-world concerns; obtaining food, dealing with common features of the environment. For example, we know that chimps can make tools that they use for obtaining food. Example: a thin green tree branch with its leaves pulled of can be used to "fish" for termites. Another example: a thick branch (club) can be used to crack open nuts. We can ask: do chimps bother to make tools if they have no practical benefit?
I assume that human language arose in the same way as other elements of primate cultures. I also think it is possible to judge the usefulness of language. Since human language can be used in so many ways, we can ask: is a specific use of language beneficial? Answering this question becomes particularly complex because language can be applied as a meta-tool to aid us in our use of other tools. In particular, I think it is important to compare how language is used to amplify the human capacity for thought and reasoning to how language is used to aid human capacities for observing the world around us.
If you add the amplifying power of human language to the normal human capacity for imagination, reasoning and logical thinking, you can easily drive the engine of human thought right off of the "rails". We need to keep looking at the world in an effort to confirm that our logic and reasoning are still in accord with reality. I think there has been an unavoidable historical process by which philosophers put too much linguistic power into thought and imagination while hoping that logic alone can keep the whole train of thought on the rails. It then remains for science to come along and try to clean up the train wrecks. Humans can be driven to use language in an attempt to deal with a real-world human concern, but there is no certainty that humans will have success. Philosophers can actually create new imaginary problems when they apply language to human concerns. Science can solve some of these self-made problems and provide new tools for dealing with problems that just cannot be solved by armchair philosophy.
PARR: As a non-scientist it would be helpful to me for a scientist such as yourself, to tell me what you understand and use the word 'instinct' for. Also does this use sanction the use of Steven Pinker in The Language Instinct, which is a defense of Chomsky's idea of Universal Grammar. In the history of Linguistics a landmark will be the book named The Linguistic Wars. It is the history of the Academic battle between Chomsky and followers versus George Lakoff, Mark Johnson and others. It is not really a philosophical issue as such, but the Rationlist philosophy of Chomsky was seen by many as being a central issue.
Most interesting human behaviors are shaped by complex interactions between what is made possible by human genes, the availability of tools, and what individual tool users experience in their environment during their lives. Human genes produce human brains and our brains are amazingly flexible in how they produce behavior. Many people think of instincts as the kinds of "fixed action patterns" that are produced by some simple nervous systems. For example, many insects do not learn to build nests. All of the key steps for nest building can be genetically programmed into the structure of an insect's nervous system. Most people would probably accept the idea that human infants have an instinct to suck. The genetic influences on complex human behaviors can best be described as predispositions towards certain behaviors. It might make sense to say that bonobos have a genetic predisposition to learn the basics of human language behavior while other species such as dogs do not. It does not bother me to say that humans have a "language instinct" in the sense that most humans are genetically predisposed to learn human language behavior. Some simple instincts do not involve learning, but complex instincts do involve learning. Since different people use "instinct" in different ways, it is probably best to just say that humans have genes that form human brains in such a way that humans can learn to use human languages. (See also: nature vs. nurture, experience vs. genetic predisposition)
Sigmund Freud used a different word for human instinct: pulsion. He saw it as different inconscious desires arising from our mind. They are impulses that lead us to do many things. Like Eros or Thanatos, the life and death pulsions, respectively.