This quote speaks to the importance of communication and timing. It suggests that not only does it take skill and tact to speak effectively and with purpose, but it also requires equal skill to recognize when it’s best to remain silent. This is a balance that is often difficult to strike, as it involves understanding the situation, the people involved, and the potential consequences of our words.

In the first part of the quote, "great tact to speak to the purpose," it emphasizes the need for thoughtfulness in our words. It’s not just about speaking, but speaking with a clear intention or purpose. This implies that our words should not be random or careless, but should be chosen with consideration for their impact.

The second part, "it requires no less to know when to be silent," underscores the importance of silence. There are times when not speaking is more powerful or appropriate than any words we might say. This could be because the situation is too charged, the other person isn’t ready to hear our words, or because our silence can send a stronger message.

In today’s world, where communication is constant and often instant, this quote is particularly relevant. With social media, emails, and instant messaging, we’re often pressured to respond immediately and constantly. However, this quote reminds us that it’s okay, and sometimes necessary, to pause and choose silence.

In terms of personal development, understanding this balance between speaking and silence can greatly enhance our relationships and interactions. It encourages us to be more mindful of our communication, to think before we speak, and to consider the power of our silence. It can also help us in conflict resolution, as knowing when to speak and when to stay silent can prevent escalation and promote understanding.