This quote essentially suggests that someone who moralizes, or preaches about morality and righteousness, is often hypocritical. It implies that people who often criticize others’ behavior or actions based on moral grounds are not necessarily morally perfect themselves. They might be using moralizing as a way to hide their own flaws and shortcomings.

The second part of the quote, referring to women, has a more nuanced meaning. Wilde suggests that a woman who moralizes is “invariably plain,” implying that she might use moralizing as a means to gain attention or respect that she feels she lacks due to her appearance. This is Wilde’s satirical commentary on the societal standards and expectations of his time.

Applying this quote to today’s world, it’s a reminder for us to be wary of those who loudly proclaim their moral superiority. It encourages introspection and humility, reminding us that we all have flaws and that it’s more important to focus on personal growth rather than judging others.

In terms of personal development, it suggests the importance of genuine self-improvement over superficial moral posturing. Instead of focusing on appearing morally superior, one should strive for true ethical behavior and integrity. It also speaks to the idea of not using moral judgment as a means to elevate oneself above others, but rather as a tool for personal and societal improvement.

However, it is also crucial to challenge the gendered assumption in Wilde’s quote. Today, we understand that women, like men, can moralize for a variety of reasons, not necessarily related to their appearance or desire for attention. It’s a reminder that we should not make assumptions about people’s motivations based on their gender.