The word "unthinking" refers to someone or something that acts without reflection or intelligent consideration. Therefore, its antonyms are words that denote intelligence, thoughtfulness, and mindfulness. These include "cogitative," "reflective," and "deliberate." Another antonym is "considerate," which suggests that one is concerned about other people's feelings and needs. "Contemplative" is another antonym that suggests someone is engaged in deep thought, meditation, or introspection. Lastly, "cerebral" is an antonym that denotes someone who is intellectual, analytical, and rational in their thinking. Embracing these antonyms can help individuals develop critical thinking skills and become more mindful and considerate in their actions.