["Behavioral Sciences &the Law, EarlyView. ", "\nABSTRACT\nThis paper uses text analysis to understand how cognitive decline affected the opinion writing of Justice Stephen Field over the course of his career. Justice Field is used as a case study because of his lengthy tenure, the fact he did not have law clerks to write opinions for him, and because it is widely known he was senile for the last part of his career. The results show that the onset of his senility altered lexical and syntactic elements of his writing style. His opinion language became simpler, yet also harder to read. The emotive language of his opinions also became more neutral toward the end of his judicial career, but these changes were marginal. This research project is the first to use a time‐serial approach to understand how judges' opinion writing may change over time given the onset of cognitive decline.\n"]