Kural - 428

Folly meets fearful ills with fearless heart;
To fear where cause of fear exists is wisdom's part

Explanation
Not to fear what ought to be feared, is folly; it is the work of the wise to fear what should be feared.

Tamil Transliteration
Anjuva Thanjaamai Pedhaimai Anjuvadhu
Anjal Arivaar Thozhil.