It is essential that a student learns critical thinking because not all the answers will come to them through a mathematical equation or through reading. They may need to reflect and analyze to form a response or judgment as they see fit. Critical thinking can be used in science, especially when asking questions about the world. Carl Sagan makes this clear in the article. “Can we know the universe?” saying, “Consequently, science sometimes requires courage – at least the courage to question conventional wisdom” (1). While it can be scary to question what we are taught, it demonstrates curiosity about the topic and opens up a new way of thinking about the people around you. Science, in a sense, is finding new information that can demonstrate that the world is what it is. It is a way of understanding the universe and how it connects to us as a whole. Thinking is a step towards acquiring new knowledge. The mind is not filled with the knowledge of the world, rather it is an empty vessel that we must fill not only by going to school, but by thinking critically about the things we are taught. Galileo Galilei's letter to the Grand Duchess is an excellent example of this. In this letter he vents his frustration with non-believers who claim that his calculations on the Copernican model are wrong and do not follow the Bible, when in fact it does. He argues: "I do not feel obliged to believe that the same God who endowed us with senses, reason and intellect has [rejected] their use and by other means to give us the knowledge that we can obtain through them" (5 ). In essence, it states that God gave us a mind because he wants us to think. It is such an important asset for a person because we have all these senses as well as the ability to reason. Education must focus on these two points because critical thinking requires the strength of both reasoning and sensitivity. Without