单项选择题

The people who are to be happy fix their attention on the conveniences of things, the pleasant pans of conversation, the well-prepared dishes, the goodness of the wines, the fine weather. They enjoy all the cheerful things. Those who are to be unhappy think and speak only of the contrary things. Therefore, they are continually discontented. By their remarks, they sour the pleasure of the society, offend many people, and make themselves disagreeable everywhere. If this turn of mind were founded in nature, such unhappy persons would be the more to be pities. The tendency to criticize and be disgusted is perhaps taken up originally by imitation. It grows into a habit, unknown to its possessors. The habit may be strong, but it may be cured when those who have it are convinced of its bad effects on their interests and tastes. I hope this little warning may be of service to them, and help them change this habit.
The phrase" sour the pleasure of society" most probably means