Why did Descartes' engage in the extraordinary method of doubting everything that is not absolutely certain?, essay help

Write a one page essay .What can we know?Why did Descartes' engage in the extraordinary method of doubting everything that is not absolutely certain? What was he trying to establish? How does he argue that we can't rely on our senses? How does he manage to cast doubt on his reason?How much can we rely on what we see and hear, think and believe? How does Descartes argue that there is anything that is really reliable? What if there cannot be any certain knowledge? Does there need to be? Is each mind's subjective knowledge that "I exist" the only absolutely certain truth? How does Descartes argue that we can rely on our reasoning and our senses after he has completed the method of doubt?What basis do we have for our knowledge? Do all beliefs have the same requirements?