“Acting man is always concerned both with "material" and "ideal" things. He chooses between various alternatives, no matter whether they are to be classified as material or ideal. In the actual scales of value material and ideal things are jumbled together. Even if it were feasible to draw a sharp line between material and ideal concerns, one must realize that every concrete action either aims at the realization both of material and ideal ends or is the outcome of a choice between something material and something ideal.
Whether it is possible to separate neatly those actions which aim at the satisfaction of needs exclusively conditioned by man's physiological constitution from other "higher" needs can be left undecided. But we must not overlook the fact that in reality no food is valued solely for its nutritive power and no garment or house solely for the protection it affords against cold weather and rain. It cannot be denied that the demand for goods is widely influenced by metaphysical, religious, and ethical considerations, by aesthetic value judgments, by customs, habits, prejudices, tradition, changing fashions, and many other things. To an economist who would try to restrict his investigations to "material" aspects only, the subject matter of inquiry vanishes as soon as he wants to catch it.”
Ludwig von Mises, Human Action, Fourth Revised Edition (San Francisco: Fox & Wilkes, 1996), pp. 233-4.