This quote prompts a profound reflection on human evolution and the role of intellect versus instinctual capabilities. Contrary to the commonly held belief that human survival mainly hinges on sensory acuity, it sheds light on the supreme importance of reasoning. While many animals rely heavily on their senses to navigate their environment and ensure survival, humans have gradually transcended these primal dependencies through the development of cognitive faculties. Our rational mind has enabled us to innovate, create tools, and build societies that lessen our reliance on raw sensory perception.

However, this intellectual prowess comes at a cost. The quote suggests that some of our original faculties have deteriorated or been suppressed as reasoning took precedence. This insight encourages a balanced perspective on progress and adaptation; evolution is not merely about gaining new traits but sometimes losing old ones when they become less necessary for survival. It also invites thoughtful consideration of what we may sacrifice as we advance technologically and intellectually. Are there sensory or instinctual qualities we undervalue or neglect, potentially at our detriment?

This reflection challenges the hierarchy we place on different human abilities and pushes us to appreciate the complexity of survival beyond sheer physicality. In the context of Edgar Rice Burroughs’ "Tarzan of the Apes," the quote resonates deeply, given Tarzan’s unique position between the animal and human worlds. It reminds us that the evolution of mankind encompasses a dynamic interplay between physical traits and intellectual capacities, ultimately shaping our place in the natural order.