Well I haven't read either of those but I have written critical response essays before. My advice would be: before you start writing, even if you have already read the essay/poems/whatever they are, read over them again to have them both fresh on your mind. While you are reading, think about your opinion on both of them. You can make an outline on a piece of paper/your computer of things you agree with and disagree with in each of them. Also, start making a summary of how they're alike and different. You need to have an introduction, that includes a thesis, and at least three body paragraphs unless your teacher told you differently. Then you need a concluding paragraph. The most important thing to remember is that you should argue your case for or against the selections you read and your opinions on them.
(Also, if you're good at math and probability, would you mind checking out my question? :) )
Answer: In philosophy, he defended a range of materialist, nominalist, and empiricist views against Cartesian and Aristotelian alternatives. In physics, his work was influential on Leibniz, and led him into disputes with Boyle and the experimentalists of the early Royal Society.
