minds, we then remember what we have forgotten in our previous existence. Since the knowledge in us is from the eternal and unchanging “Form”, the knowledge in us is unchanging and eternal. In similar to Plato’s view in Meno, Plato’s view in Republic has two categories of knowledge. He says “there are two ruling powers, and that one of them is set over the intellectual world, the other over the visible” (Plato 47). On that account, the knowledge we have is from both our perception and our intellectual world. What we perceive is not true and that is not knowledge. When we perceive something that comes in a pattern and has a principle, our reason will process into hypothesis by opinion and our soul will recognize that by reason (Plato 48). Mathematical formulas can be good examples in this argument because mathematical formulas are eternal and unchanging. For instance, before we recognize that “a+b=c” as a hypothesis, we must have had experience of measuring a physical right triangle in order to make sure that hypothesis becomes true at all time. When the hypothesis is true, it then becomes knowledge. That is the procedure of the intellectual world. The intellectual world that is our knowledge is eternal and unchanging. In a similar way, the view in Theaetetus’s case, Plato believes that some true opinions or beliefs can be knowledge. In Theaetetus, Plato thinks knowledge is “right opinion with rational definition or explanation” (Plato 60). For instance, when we hold a true opinion about a right triangle formula, we need to justify that true opinion by our rationality; we know that it becomes knowledge if that formula works with all cases. As a result, that knowledge is unchanging and eternal and knowledge timelessly exists. The difference of knowledge in Meno, Republic, and Theaetetus is the degree of weaknesses in developing the argument of finding out w...
