For those who may be interested:
Fr. Alphonsus Rodriguez, S.J.[1] (d. 1616) has sometimes been called a "Christian Seneca".[2]
I had never heard of him or his major work Practice of Perfection and Christian Virtues until 2004, when someone I met on a retreat recommended that I hunt down a copy of Joseph Rickaby's[3] masterful translation from the original Spanish.[4]
I had the opportunity to read through PPCV over the period of about a year back in 2007–08, and I can only say that it leaves a remarkable and lasting impression. I would think his treatises on humility, examination of conscience, and mental prayer (meditation) would be of great interest even to those who aren't particularly religious — i.e. the practical wisdom contained therein is like a toolkit for coming to "know oneself" for true.
[1] https://en.wikipedia.org/wiki/Alonso_Rodriguez
[2] http://www.jstor.org/discover/10.2307/2540029
[3] http://en.wikipedia.org/wiki/Joseph_Rickaby
[4] https://archive.org/details/PPCV-Manresa