GK Chesterton is great on this subject, in Science and the Savages from Heretics (1905):

The secret of why some savage tribe worships monkeys or the moon is not to be found even by travelling among those savages and taking down their answers in a note-book... The answer to the riddle is in England; it is in London; nay, it is in his own heart. When a man has discovered why men in Bond Street wear black hats he will at the same moment have discovered why men in Timbuctoo wear red feathers. The mystery in the heart of some savage war-dance should not be studied in books of scientific travel; it should be studied at a subscription ball. If a man desires to find out the origins of religions, let him not go to the Sandwich Islands; let him go to church. If a man wishes to know the origin of human society, to know what society, philosophically speaking, really is, let him not go into the British Museum; let him go into society.

This total misunderstanding of the real nature of ceremonial gives rise to the most awkward and dehumanized versions of the conduct of men in rude lands or ages. The man of science, not realizing that ceremonial is essentially a thing which is done without a reason, has to find a reason for every sort of ceremonial, and, as might be supposed, the reason is generally a very absurd one — absurd because it originates not in the simple mind of the barbarian, but in the sophisticated mind of the professor. The learned man will say, for instance, "The natives of Mumbojumbo Land believe that the dead man can eat and will require food upon his journey to the other world. This is attested by the fact that they place food in the grave, and that any family not complying with this rite is the object of the anger of the priests and the tribe." To any one acquainted with humanity this way of talking is topsy-turvy. It is like saying, "The English in the twentieth century believed that a dead man could smell. This is attested by the fact that they always covered his grave with lilies, violets, or other flowers. Some priestly and tribal terrors were evidently attached to the neglect of this action, as we have records of several old ladies who were very much disturbed in mind because their wreaths had not arrived in time for the funeral." It may be of course that savages put food with a dead man because they think that a dead man can eat, or weapons with a dead man because they think that a dead man can fight. But personally I do not believe that they think anything of the kind. I believe they put food or weapons on the dead for the same reason that we put flowers, because it is an exceedingly natural and obvious thing to do. We do not understand, it is true, the emotion which makes us think it obvious and natural; but that is because, like all the important emotions of human existence it is essentially irrational. We do not understand the savage for the same reason that the savage does not understand himself. And the savage does not understand himself for the same reason that we do not understand ourselves either.

The obvious truth is that the moment any matter has passed through the human mind it is finally and for ever spoilt for all purposes of science. It has become a thing incurably mysterious and infinite; this mortal has put on immortality. Even what we call our material desires are spiritual, because they are human. Science can analyse a pork-chop, and say how much of it is phosphorus and how much is protein; but science cannot analyse any man's wish for a pork-chop, and say how much of it is hunger, how much custom, how much nervous fancy, how much a haunting love of the beautiful.

http://gutenberg.net.au/ebooks13/1301191h.html#ch11