In the "argument from knowledge" also proposed by Frank Jackson, known as Mary's room, in his article entitled Epiphenomenal Qualia, Jackson argues against physicalism and he idea that the universe, including everything conscious/mental, is entirely physical. Even though Jackson no longer agrees with it, it is still considered one of the most important arguments in the philosophy of mind. In this article I will explain the argument, assess its validity and soundness, explain what problem it poses for physicalism, the basic structure of Lewis's response, and whether Lewis's response is convincing. The knowledge argument is made valid. If an argument is valid, it means that the structure ensures that if the premises are true, then the conclusion must also be true. The knowledge argument is not valid, because if it were, it would mean that physicalism is false; but physicalism is not false, so the knowledge argument is valid. I believe this physicalism is true and that everything that could/exists is either physical or depends on the physical. Since I believe the knowledge argument asserts that physicalism is true, the argument is valid. The knowledge argument can be simply presented as one who can know all the objective and physical facts about conscious experiences, but still does not fully know human conscious experiences, therefore physicalism is false. Frank Jackson has two cases regarding physicalism: the Mary case and the Fred case. The Fred Case is a case where a man named Fred sees two colors; his consciousness developed its own use of the two words red and red. "In any case, he explains to us that it would be completely wrong to think that because "red" appears both in "red (1)" and in "red (2)", these two colors are nuances of the... .middle of paper ......the currency of ary after leaving the room in black and white. The ability hypothesis simply states that knowing what an experience is like is equivalent to knowing how to imagine having an experience. I agree with Lewis because there are no facts to support knowing how to do a certain action because you have to actually experience something yourself to know how to do something. In conclusion, the knowledge argument proves to be a valid argument, but not the sound. I explained all the premises that accompanied the knowledge argument and what problem affects physicalism. I have also examined and posted Lewis's response to the knowledge argument, and whether or not it is convincing. Overall, I believe that almost everything in this universe is physical. The argument from knowledge will always be known as one of the most important arguments in the philosophy of mind..