The Constitution specifically stated Congress' method of imposing direct taxes, by requiring Congress to distribute direct taxes in proportion to each state's population "determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons". It has been argued that head taxes and property taxes (slaves could be taxed as either or both) were likely to be abused, and that they bore no relation to the activities in which the federal government had a legitimate interest. The fourth clause of section 9 therefore specifies that, "No Capitation, or other direct, Tax shall be laid, unless in Proportion to the Census or enumeration herein before directed to be taken."