This quote is a metaphorical representation of the power of intellect. The cleaver is a tool used for cutting through things, often used in butchery to separate meat from the bone. Here, it symbolizes the ability of the intellect to penetrate the surface of things, to dissect and analyze them, and to reveal their inner workings or secrets.

When Thoreau says "the intellect is a cleaver," he is suggesting that our intellect is a tool that allows us to cut through the superficial appearances of things and get to their essence. It discerns, meaning it recognizes and understands things that are not immediately apparent. It rifts its way, meaning it creates a path or opens a way through diligent and persistent effort.

In the context of personal development, this quote emphasizes the importance of using our intellect to understand the world around us and ourselves. It suggests that we should not take things at face value, but instead use our intellect to delve deeper. In other words, it’s about critical thinking. It’s about not accepting information as it is, but analyzing it, questioning it, and making our own judgments.

In today’s world, this idea is more relevant than ever. We are bombarded with information from all sides – social media, news, advertisements, etc. It’s easy to accept this information passively, without questioning its validity or understanding its implications. But Thoreau’s quote urges us to use our intellect as a cleaver, to cut through this overload of information and discern its true nature.

In a broader context, this quote can also be seen as a call for scientific inquiry and rational thinking. The secrets of things, the truths of the universe, are not readily apparent. They need to be discerned through rigorous intellectual effort, through observation, experimentation, and analysis. This is the essence of the scientific method, and it’s how we have come to understand many of the fundamental truths about the world we live in.