But such exceptional cases should not shake our confidence in the fundamental principles of decoration. It is true that these principles cannot be reduced to formulas to be applied invariably in all cases, and it is unreasonable to assume that any form of treatment is the only one possible in any given case. Modifications in the application of these principles are always possible, but the principles themselves are as unalterable as the Mosaic law. One is, indeed, tempted to summarize them thus as the
TEN COMMANDMENTS OF DECORATION
Thou shalt have no household gods except those that be beautiful or those that be useful.
Thou shalt not make unto thyself any likeness that is in the heaven above or in the earth beneath, or in the waters under the earth, that does not find an appropriate setting in thine house.
Thou shalt not look in vain upon the creations of the great masters of decorative art.
Remember the colour scheme and keep a good background.
Honour the original design, however old it may be, and make the most of it. Thou shalt not hesitate to correct the blunders of faulty design and bad architecture.
Thou shalt not kill thy neighbours or thy friends with over-decorated wall papers or oppressive decorations of any kind.
Thou shalt not bring together incongruous articles nor permit insane arrangements of anything that is thine.
Thou shalt not permit any false note to mar the harmony of thy decorations.