118 NATURE OF CAPITAL AND INCOME [CHae. VII 
never command a money rent to the landlord if it did 
not also yield shelter to the tenant, and even from the 
standpoint of the landlord the receipt of the money only 
intervenes as a medium for payment of his own rent and 
other expenses of living, in other words for securing his 
enjoyable income. 
Income is, then, a very general concept. It consists of 
services rendered by capital. We have seen that under it 
are included several special concepts : Social income, indi- 
“vidual income, money income, natural income, and enjoyable 
income. We shall soon see that the net income of society 
or of an individual consists wholly of enjoyable income. 
This is because the non-enjoyable elements of income, 
such, for example, as money-income, are all exactly offset 
by equal items of outgo. But the non-enjoyable elements 
are none the less a part in the grand total, and, in fact, 
by far the greater part. The money-income of ordinary 
bookkeeping forms the bulk of any true inventory of in- 
come; but its significance cannot be understood until its 
counterpart in outgo is also taken into account, nor until, 
in fact, a complete picture of all elements of income is 
brought before the mind’s eye. To present this picture 
will be the object of the next three chapters.