DEMAND 
47 
as of his independent individuality, but also 
that an individual’s system of demand, taken 
as a whole, tends to settle into a particular 
form. Some appreciable shock is needed to 
shake it out of this form. Hence it is common 
to say that expenditure is settled by standards 
of life. By a standard of life is meant the 
common form which expenditure tends to 
assume in any given class of the community, 
or the modes of disposing of income which are 
typical of a class. For some purposes it is 
convenient to distinguish between the indi 
vidual’s standard of living and the standard 
of living of the class to which he belongs. The 
former is usually a species of the latter—the 
latter modified by his idiosyncrasies. It is 
only in exceptional cases that the standard 
of any person is actually in conflict with 
the standard of his class. The individual’s 
standard is largely settled by his habits, and 
habitual action is universally more difficult 
to modify than action which is not habitual. 
I intend now, despite its alleged difficulty, 
to introduce a conception about which there 
has been much controversy, but one which, 
nevertheless, in my opinion, is likely to play in 
the future a leading part both in the develop 
ment of economic theory and in the practical 
application of economic teaching. It is one