The phrase "throwing doubt on" can be replaced with numerous antonyms, including affirming, confirming, corroborating, validating, affirming, assuring, and supporting. These words all share a similar meaning, which is to provide evidence or proof that something is true or accurate. When we affirm or confirm something, we are expressing confidence in its validity or reliability. Corroborating or validating something means providing additional evidence or support that strengthens its credibility. Supporting or assuring something means confirming our belief in its accuracy or truthfulness. In short, by using antonyms for "throwing doubt on" we can express confidence in our opinions, beliefs, or ideas.