The difference between "What Cause" and "What Purpose". The aim of Philosophy is to pursue knowledge, understanding, and wisdom (usually in that order). There are many branches of Philosophy, and each branch has it's own limitations, which are not usually limitations of the whole of Philosophy, but merely of that one branch. Science is a branch of Philosophy, and as such must also have its own limitations that are not shared by the whole pursuit of Philosophy. One of these limitations, I think, is that Science cannot answer "why" questions. Science is very good at answering "what", "where", "when", "which", "how", and many other kinds of questions, but it always fails at "why" questions, because it's not designed to deal with them. The reason I say it's not designed to deal with them is because it is entirely based on Inductive Logic (that which happened in case A, B, C, and D will happen in case E). The Scientific Method requires that a certain experiment be repeatable, in order for it to "prove" an hypothesis, but this (again) is induction. Now, Inductive Logic is based on the idea of Causality. If there were no cause-and-effect then there could be no assumption that case A, B, C, and D were in any way related, so as to assume that case E (which occurs under exactly the same circumstances as the previous cases) will have anything like those results. Now, the reason that the title of the thread is "The difference between 'what cause' and 'what purpose'" is because there are indeed "why" questions that can be answered by Science, but these take on a different form then the kind that I was referring to by previous mention of "'why' questions". You see, "what cause" questions can be phrased as "why" questions (though they can also be phrased otherwise, and so Science never really has to answer a question in the "why" format), but Science is still equipped to answer them. For example, if I ask, "why does the Earth revolve around the Sun", Science can answer "because inertia is keeping the Earth moving, while gravity keeps it from leaving the Sun" (Note: This answer can be re-phrased as "this effect is caused by the combined effects of inertia and gravity"). However, the "why" question of the form "what purpose" cannot be re-phrased, and can also not be answered by Science. As an example, after my having answered that inertia and gravity keep the Earth in orbit around the Sun, one could as "Why does gravity exist?". This is a "what purpose" question, and is meaningless in Science. The scientist would probably answer "it just works that way" or "that's just the way it is", since anything further explanation of their purpose would require something outside of the Inductive system(be it belief, faith, credulity, or whatever else). In summary: Science, due to its Inductive nature, is bound to Causality, and thus cannot be used to answer "why" questions of the form, "what purpose". Science can answer "why" questions of the form, "what cause", but these can always be re-phrased into something other than "what purpose" (i.e. "Why does the Earth revolve around the Sun?" = "What causes the Earth to revolve around the Sun?" or even "How does the Earth stay in orbit around the Sun?").