With a further advance in culture this tabu may change into simple custom of a more or less rigorous character; but whatever be the theoretical basis of the distinction which is maintained, whether it be a tabu or a larger conventionality, the features of the conventional scheme of consumption do not change easily.

When the quasi-peaceable stage of industry is reached, with its fundamental institution of chattel slavery, the general principle, more or less rigorously applied, is that the base, industrious class should consume only what may be necessary to their subsistence.

In the nature of things, luxuries and the comforts of life belong to the leisure class.

Under the tabu, certain victuals, and more particularly certain beverages, are strictly reserved for the use of the superior class.
The ceremonial differentiation of the dietary is best seen in the use of intoxicating beverages and narcotics.

If these articles of consumption are costly, they are felt to be noble and honorific.