impartial (adj)

showing lack of favoritism

"the cold neutrality of an impartial judge"

unprejudiced, impartial (adj)

free from undue bias or preconceived opinions

"an unprejudiced appraisal of the pros and cons"; "the impartial eye of a scientist"

impartial (Adjective)

Treating all parties, rivals, or disputants equally; not partial; not biased; fair.

impartial

Impartiality (also called evenhandedness or fair-mindedness) is a principle of justice holding that decisions should be based on objective criteria, rather than on the basis of bias, prejudice, or preferring the benefit to one person over another for improper reasons.