The phrase "art the horizon" implies a sense of creativity or artistry in the future, beyond the visible horizon. Some antonyms for this phrase could be "destroy the horizon," "lack of imagination," or "conservative thinking." These phrases suggest a negativity surrounding the future, with a lack of creativity and innovation. Another antonym could be "stay within the horizon," implying a sense of comfort and safety in the present, without the risk of exploring new and uncharted territories. Regardless of the antonym, it is important to always strive towards progress and growth, continuously pushing the boundaries and exploring new ideas.