Do we need both and can both be both beneficial and detrimental! Please provide definitions for both. My own definition is based on value. Good is beneficial and evil is detrimental. Based on another used definition, good amounts to liking something and evil amounts to disliking something. My own view and answer is yes ... Food and evil can both be beneficial and detrimental, which leads to logic, critical thinking, and ability to reason and or understand individual circumstances and how the concepts of good and evil might apply to them.