This quote by Leonardo da Vinci suggests that the use of other authors’ thoughts and ideas in a discussion is more an act of memory rather than intelligence. Da Vinci seems to be implying that true intelligence lies not in merely remembering and repeating what others have said, but in formulating and expressing one’s own unique thoughts and ideas.

The quote also suggests that a person who constantly relies on others’ ideas is not fully utilizing their own intellectual capabilities. It’s like using a crutch to walk when one’s legs are perfectly healthy. This doesn’t mean that one should disregard the thoughts and ideas of others entirely. Rather, it means that one should use them as a springboard for their own thinking and not as a substitute for it.

In today’s world, this idea is particularly relevant. With the internet, we have easy access to an abundance of information and ideas. It’s tempting to simply parrot these ideas instead of thinking critically and forming our own. This can lead to echo chambers, where the same ideas are repeated over and over again, stifling original thought and creativity.

In terms of personal development, this quote is a reminder to always think for ourselves. While it’s important to learn from others, we should also strive to develop our own understanding and perspectives. This involves questioning and critically analyzing the ideas we encounter, and not accepting them at face value just because they come from an ‘authority’.

In essence, Da Vinci is encouraging us to be independent thinkers and to value our own intellectual capacities. We should be confident in our ability to contribute unique and valuable insights to any discussion, instead of merely echoing what has already been said.