The Theory of Opposites posits that treatment uses opposites to counterbalance symptoms.

• A. Vaccination
• B. Germ theory
• C. Using opposites to counterbalance symptoms
• D. Spiritual healing

Answer: (C)

The main idea here is balancing the body by using the opposite quality to counteract a symptom. In ancient and medieval medical thinking, illness was seen as an excess of a particular quality (like hot or dry), and remedies aimed to restore harmony by applying the opposite quality (cooling for heat, moisture for dryness, and so on). This underpins the Theory of Opposites: treatments are chosen to counterbalance what’s out of balance, with practices such as diet, regimens, and procedures like purging or bleeding used to reestablish equilibrium. The other options describe different ideas about disease—vaccination develops immunity, germ theory explains causes, and spiritual healing relies on non-physical remedies—so they don’t fit the concept of balancing qualities with opposites.