In Walter Isaacson's biography "Benjamin Franklin: An American Life," Franklin reflects on his experiences with metaphysical reasoning. He expresses a strong dissatisfaction with the uncertainties and complexities involved in such studies, which led him to abandon them in favor of more fulfilling pursuits. His distaste for abstract philosophical debates illustrates his pragmatic approach to knowledge and learning.

Franklin's decision to move away from metaphysics highlights his preference for practical and concrete ideas that provide clear insights and benefits. This shift reflects his broader philosophy of seeking useful knowledge that can be applied to real-world situations, thereby shaping his contributions as a statesman, inventor, and thinker.