Causal necessity typically receives only oblique attention. Causal relations, laws of nature, counterfactual conditionals, or dispositions are usually the immediate subject(s) of interest. All of these, however, have a common feature. In some way, they involve the causal modality, some form of natural or physical necessity. In this paper, causal necessity is discussed with the purpose of determining whether a completely general empiricist theory can account for the causal in terms of the noncausal. Based on an examination of causal relations, laws of nature, counterfactual conditionals, and dispositions, it is argued that no reductive program devoid of essentialist commitments can account for all the phenomena that involve causal necessity. Hence, neo-Humean empiricism fails to provide a framework adequate for understanding causal necessity.