There are two types of questions that we know have clear, real answers. The first type of question is empirical, which is to say it can be answered by systematic observation. How much money is in my bank account, how much weight can a particular bridge support and how much money will this tax raise bring to the treasury are all examples. The second type of question is formal. Given certain axioms, and rules for manipulating them, we can get an answer through pure calculation. This kind of question cannot answer questions about the world, except in so far as the axioms and the rules for manipulating them resemble the world as it exists. Taxonomy, logic, and math are all good examples of the second type of question.
For a well formed question of these sorts, even if we do not know the answer, we do know roughly what form an answer would take, that is we can determine whether a particular answer is a possible answer even if we can’t tell if it is a correct answer. We should be able to determine what sort of reasoning, what sort of demonstration, what sort of arguments would be relevant, and which would not.
Where the concepts are clear and their shape is generally accepted, and where the appropriate shape of reasoning is agreed on, only there is it possible to construct something resembling universal knowledge, of whatever kind. Where the questions are not clear, where a concept is not well defined, and no one can agree on what an answer would look like, and the methods and qualifications to answer the questions are entirely in dispute, then we can construct only a pseudoscience, or if we are lucky, a protoscience.
There is however a third category of questions, those which cannot be formulated in either of the two categories which have well defined answers. Does free will exist? What is justice? How can I know whether an action is just? Why should I obey another? We discover that we are not sure, from the very outset, what a clear answer to these questions would look like, whether inductive or deductive. These are the philosophical questions.
Now the history of human knowledge has been the gradual shifting of the philosophical questions into one or the other of these two compartments. The nature and composition of the stars was once a philosophical question, and it could not be clear ahead of time what part should be played by observation and what by a priori teleological notions, and the questions asked could not be neatly divided into formal and inductive categories. As methods competed and technologies of observation and technique advanced, the questions became well formed, and the science of astronomy was born. You can begin to see the outlines of the death of philosophy of mind and the birth of a science of mind already, or hedonic philosophy being transformed into a science of happiness. For studies at this boundary, not quite science and not quite philosophy, meaningful dialogue can take place. A philosopher who attempts to answer an empirical question, without using an empirical method, is sure to be spouting nonsense, and a scientist who attempts to answer a non-empirical question using an empirical method will be answering a different question than she thinks.
There is however also a category of philosophical questions which stubbornly resist resolution into well behaved categories. The efforts at least from Plato onwards to found a systematic scientific account of ethics or aesthetics has repeatedly failed. Relativism, emotivism, skepticism always break back in. Ryan condemns all of philosophy, however his particular concerns seem to be with what is broadly politics, that is how we should treat others and what the ultimate aim of our actions should be. But this is not an empirical question, like how we *do* treat people or more specifically who treats whom in what way, when and where and under what circumstances. It is not a clearly deductive question either, like whether a particular action violated custom or law.
What makes such questions as justice and ethics properly philosophical is precisely that there is such widespread disagreement about what kind of reasons are valid, and what the shape of a valid argument looks like. The methods of answering look very different for theists and atheists, reductive materialists and Christians, Romantics, Marxists, Feminists and Nihilists. The differences between them are not empirical disagreements, nor are there a set of axioms to which we can garner universal consent, nor even a process for generating axioms. The reason why philosophy is necessary, the reason why it arose in the first place, is precisely because of this disagreement.
If everyone agreed on ultimate ends, the questions that are supposed to arise out of political and ethical philosophy would reduce to a inductive problem of what sort of actions increased utility, or a statistical analysis of what actions in what situations increased happiness. If everyone agreed on axioms, or agreed on the process for generating axioms, then politics and ethics would reduce to calculation based on the ten commandments or the categorical imperative. It is precisely that persistent disagreements, systematic disagreements, continue to exist, that the chain of arguments do not follow the same family of paths, that the form of solutions is fundamentally unresolved, that requires the answer remain philosophical.
It is entirely legitimate, and possibly correct, to argue that philosophical methods cannot produce truthful knowledge about the world or ourselves, and is at best rationalizations of deeper processes. Prior to the 18th century or so slavery was an accepted part of the social order, and ethics was concerned mainly with the appropriate manner in which slaves should be treated. People with as contradictory ethical systems as the Epicureans and the Stoics neverless agreed that slavery was acceptable, as did the medieval Christians and Muslims and Hindus. By the end of the twentieth century, neo-stoics, neo-Epicureans, Utilitarians and Deontologists, no matter their other substantial disagreements all agree that slave holding is impermissible. It was not new knowledge, but new social convention that changed the ethical theory. By contrast stoic logic, though incomplete, is as valid now as when it was formulated, and the Greek proofs that the world is round are as acceptable today as when they were first observed. Answers to philosophical questions are genuinely different than answers to well formulated questions.
Nevertheless, to argue that everyone knows what actions will increase happiness, and further that everyone wants to increase their own happiness and that of others is a well formulated empirical question, and one need only look at the contrast between the actions of the average person compared the findings, such as they are, from happiness research to indicate that either people do not know what makes them and others happy, or else that they do not think that happiness is the meaning of life and basis of ethics. However humans are social, and so the game of giving and asking for reasons must continue. The problem of competing ethical systems is not that different people might disagree about the best way to achieve identical ends, but that different people will do different things for reasons that others will find unacceptable, or towards ends that they find incomprehensible. To argue that it does not matter why a person gives money to the homeless so long as he does so, is only a gracious concession that it does not matter why someone agrees with you, so long as they do.