Literally: correct – correct – mistake – mistake
Alternately: Fairness; honesty; impartiality. Calling correct things correct and mistaken things mistaken, objectively, instead of allowing one’s biases to become involved.
Notes: May also be written with the repeating mark as 是々非々. Keep in mind that in addition to the “meanings” given above, 是 can also be rendered in English as “this,” “justice,” etc. depending on the situation; 非 can be a negation prefix.