To consort with the crowd is harmful; there is no person who does not make some vice attractive to us, or stamp it upon us, or taint us unconsciously therewith. Certainly, the greater the mob with which we mingle, the greater the danger.
– Seneca
Be not deceived: evil communications corrupt good manners.
– 1 Corinthians 15:33
As a social animal, man craves the company and the admiration of others, but this is only the monkey mind seeking attention. Certainly, connection with the tribe is necessary for our physical and emotional well-being; however, letting the culture and the morals of the tribe dictate your thoughts and actions is equally detrimental.
As with all things, we are subject to the environments we live in, be they physical, social, or cultural. Being a Stoic means striving to live a life of virtue and, equally important, adopting a rational view of the world and using that to make decisions in support of my Stoic principles.
Just as a fish cannot reject the water they swim in, I cannot isolate myself from my environment. However, the wise fish is the one who recognizes that the water has become polluted and swims to cleaner waters, not the one who attempts to fling themselves out of the water to die on the land, nor one who denies that the water is polluted until too late.