tough-minded

selväjärkinen Not distracted from actual facts by enticements, intimidation, or sentimentality; steadfast in one's actions, commitments, beliefs, etc.
1920, w:F. Scott Fitzgerald|F. Scott Fitzgerald, "Benediction":

This was the Society of Jesus, founded in Spain five hundred years before by a tough-minded soldier who trained men to hold a breach or a salon, preach a sermon or write a treaty, and do it and not argue.

Britain's Peregrine Worsthorne, 36, is a tough-minded Tory journalist with scant regard for preconceived opinions—his own or anybody else's.

They considered themselves tough-minded realists, and regarded doubters as fuzzy-minded whiners.