Martin Luther, the 16th century religious thinker and reformer of Western Christendom, is usually depicted as a staunch opponent of Aristotle, especially when it came to using Aristotle’s ideas in religious intellectual reflection. Our article aims at examining Luther’s use of selected key concepts and ideas from Aristotle, while at the same time criticizing other concepts as dangerously misleading. The selection of concepts is based on their occurrence and relevance for scholastic theology, which Luther evaluates critically. Moreover, we propose to distinguish between Luther’s relationship to Aristotle’s ideas as these became known to Luther through the available Latin translations of his works, and between Aristotelian concepts that had been employed by selected scholastic theologians. There appears to be a development of emphasis in Luther from his early years to more mature (and expressive) views. Another important distinction that we wish to propose in assessing Luther’s attitude to Aristotle is whether his ideas are used coram hominibus (i.e., dealing with realities of this earthly realm without a direct linkage to salvation) or coram Deo (i.e., dealing with the relationship between God and humans in the history of salvation). A proper evaluation of Luther’s views and use of Aristotle has direct theological and ethical consequences, both in the realm of individual ethics as well as in the dimension of social and political interaction of humans.