The failure of palm readers to identify the causal connection between the lines on a person's hands and his or her life indicates that the theory of palm reading is:

Science is a system for collecting knowledge to understand the world, while superstition is a non-scientific belief in magical connections. Superstition can be religious, cultural, or personal. 
Superstition and science can conflict in medical practices. For example, traditional healers may use superstition to treat health problems, but medical professionals use evidence-based practices. Traditional healers may use unsterilized instruments in unsafe environments, which can lead to harmful, potentially fatal impacts on patients.