Truth is not so threadbare as speech, because fewer people can make use of it" is a profound statement that emphasizes the rarity and value of truth compared to speech. Speech is "threadbare" or common and worn out because everyone can speak, but not everyone can speak the truth. In other words, while words are easily spoken and often overused, truth is a much rarer commodity. It’s not something that everyone can grasp or willing to use, making it more precious and less worn out.

The quote implies that truth requires a level of courage, wisdom, and integrity that not everyone possesses. It suggests that many people may resort to lies, half-truths, or omissions either because the truth is uncomfortable, inconvenient, or because they lack the moral fortitude to be truthful.

In today’s world, this idea is highly relevant. In the age of social media and "fake news", speech is plentiful, but truth often seems hard to find. People are bombarded with information, but much of it is unverified or even deliberately misleading. The truth, therefore, becomes even more valuable. It’s not just about fact-checking, but about having the discernment to distinguish between what’s genuine and what’s not.

In terms of personal development, this quote may inspire us to value truth more and strive to be among those who can make use of it. It encourages us to cultivate honesty, integrity, and discernment. It reminds us that while it’s easy to speak, it’s more challenging—and ultimately more rewarding—to speak the truth. This could mean being honest with ourselves about our strengths and weaknesses, being truthful with others even when it’s uncomfortable, or standing up for the truth even when it’s unpopular.