What would lead a historian to consider two events to have a relationaship of correlation rather than causation?

A historian might consider two events to have a relationship of correlation rather than causation if they observe that the events occur simultaneously or show a statistical association but lack a direct cause-and-effect link. This could be due to external factors influencing both events or mere coincidence. Additionally, if the evidence does not support a clear mechanism by which one event directly influences the other, the historian would lean towards correlation. Contextual analysis and the examination of alternative explanations also play a crucial role in this determination.