The world you think exists does not actually exist. You are just a brain in a petri dish. Everything you perceive, including this article, is an illusion created by evil scientists through neuroelectronic signals. Question: How do we know if we are in the above situation or if we are living in the real world? Skeptical debates are difficult because the common premises and inferences used on a daily basis are often locked up in such debates, and the threshold of knowledge in front of us is too high to jump through. If "seeing is believing", is there really a glass of water on the table? I really don't know. If the process of calculating the math in my remove background from image head may be controlled by demons, does one plus one really equal two? I really don't know. It is worth noting that this kind of skeptical-flavored thinking is not limited to philosophical discussions. Even in day-to-day or social discussions, someone may place the burden of proof on others to unusual levels in order to win an argument or avoid questioning, such as: Meizi: Who told you to hit me first! Xiaohua: When will I hit you? A few minutes, a few seconds, you say. or: Aquarius: What if society disintegrates after same-sex marriage is passed? Mud: Why does society disintegrate? France and Canada both have same-sex marriages, and that's fine. Aquarius: If they are fine, that doesn't mean Taiwan will be fine. Can you guarantee it? ↑ Further reading: "Is the demise of mankind more serious than Li Tianzhu's discriminatory remarks? > Of course, this type of skeptical taste argues in a different way than academic philosophical skepticism, where these contenders are usually arguing on individual cases and are not prepared to face anything else with the same rigor. However, in terms of "raising the threshold of knowledge / raising the burden of proof", the two can still be compared together. If this skeptical taste of thinking bothers you, there are some directions of struggle to consider.