This quote suggests that our perceptions are often colored by our personal biases, prejudices, or states of mind. When Pope says "all seems infected that th’ infected spy," he means that a person who is tainted or corrupted in some way will tend to see corruption everywhere else. Similarly, "all looks yellow to the jaundiced eye" refers to the medical condition of jaundice, which can turn the whites of one’s eyes yellow and cause a yellowish tint to one’s vision. This is a metaphor for how our personal perspectives can color our view of the world.
Applying this idea to today’s world, we can see how it reflects in our societies and politics. For instance, someone who is deeply distrustful of government might see corruption and conspiracy in every policy or decision, even when there is none. It could also apply to how we view people from different cultures, races, or religions. If someone has deeply ingrained prejudices, they might interpret all actions from people of that group through that biased lens.
In terms of personal development, this quote can remind us to be aware of our own biases and how they might be affecting our perception of reality. It encourages introspection and self-awareness. If we are feeling particularly negative, for instance, we might start to see everything in our lives in a negative light. Recognizing this can help us to challenge these perceptions and strive for a more objective view of the world.
Furthermore, it encourages us to develop empathy and understanding for others. Just as our experiences and mindset shape our view of the world, so do other people’s. Recognizing this can help us to be more understanding and accepting of differing perspectives.
