Logicians and mathematicians often use diagrams. Diagrams are helpful in coming up with a proof and understanding logical and mathematical concepts. But can a diagram be a proof? Several attempts have been made to provide a positive answer to this question. In this paper, I will examine the relationship between a proof and logical/mathematical reasoning and show that there are two kinds of norms of reasoning that a proof must embody. Based on this examination, I will show that some of the reasons that have been given in the literature to support the claim that diagrams can be proofs are problematic. More importantly, I will argue that the question is, in fact, misguided. I will conclude by suggesting an alternative way of understanding the nature of proofs.