Percentage of earnings is just equity. They're different, but not ethically. Slavery would be forcibly taking 100% of an individual's equity, but given that ISA

Percentage of earnings is just equity. They're different, but not ethically. Slavery would be forcibly taking 100% of an individual's equity, but given that ISAs are both optional and a minor percentage (Lambda's was 18% when I went thru), the comparison is unreasonable.