This quote suggests that wherever there is secrecy or mystery, wrongdoing or dishonesty are often close at hand. The idea here is that truth and honesty thrive in transparency, while vice and roguery – words used to denote morally reprehensible behavior or deceit – find their breeding ground in the shadows of secrets and mysteries. The implication is clear: if you want to avoid falling into vice or roguery, you should strive for openness and clarity in all your actions.

In a broader context, this quote might be seen as a commentary on the dangers of secrecy within societies. When information is withheld from the public, it creates room for manipulation, deception and corruption. Transparency acts as an antidote to such vices by ensuring accountability.

Applying this idea to personal development involves embracing honesty not just with others but also with oneself. It’s about being transparent about your intentions, desires, strengths and weaknesses rather than hiding behind a façade of pretense or denial.

In today’s world where fake news proliferates on social media platforms and misinformation campaigns are rampant across various mediums; Johnson’s quote rings particularly true. Secrecy breeds suspicion while openness fosters trust – a principle that applies whether we’re talking about interpersonal relationships or international diplomacy.

On an individual level too; when people keep secrets from their loved ones it can lead to hurt feelings, misunderstandings & broken trust which may take years to mend if at all possible. On the other hand being open & honest helps in maintaining healthy relationships & contributes positively towards personal growth & development.

Thus Johnson’s words serve as timeless wisdom advocating transparency over secrecy & honesty over deceit both at societal level as well as individual one.