Seneca’s complete Dialogues include the classic Aubrey Stewart translations and Damian Stevenson's version of On the Shortness of Life:
On the Shortness of Life (De Brevitate Vitae)
Of a Happy Life (De Vita Beata)
Of Providence (De Providentia)
On the Firmness of the Wise Man (De Constantia Sapientis)
Of Anger (De Ira)
Of Leisure (DeOtio)
Of Peace of Mind (De Tranquillitate Animi)
Of Clemency (De Clementia)