Henry Phelps Brown - The Inequality of Pay

In the agelong outcry against the contrast of poverty and riches, the rich man used to be seen as essentially the man of property. High incomes came from great possessions. The landowners stood over against the landless labouring people. As time went on, the forms of property that yielded income came ever more conspicuously to include commercial and industrial capital, but in the mind's eye of the social analyst, reformer and revolutionary alike, labour remained undifferentiated. Only in more recent years has attention begun to be directed to differences in the earnings of different kinds of labour as a major source of inequalities of income.