To assess a patient's ability to reason abstractly, you would ask them to:

The ability to reason abstractly involves understanding and interpreting concepts that are not immediately obvious or literal. Asking a patient to state the meaning of a common proverb is a direct way to assess this skill, as proverbs often contain metaphorical meanings that require thought and interpretation beyond their literal definitions.

For example, a proverb like "A stitch in time saves nine" implies the importance of addressing problems early before they escalate. Understanding this requires the ability to grasp the underlying message about foresight and cost vs benefit, which exemplifies abstract reasoning.

In contrast, describing what they would do if there was a fire in the house tests practical reasoning and decision-making skills rather than abstract reasoning. While it does require some level of logical thought, it is based more on concrete scenarios rather than abstract thinking. Counting backwards by sevens is a test of cognitive function and attention but does not assess abstract reasoning skills, as it is a straightforward task that does not involve interpreting underlying meanings or concepts.

Thus, discussing a common proverb is the best choice for gauging a patient's capability in abstract reasoning.