Archimandrite Sophrony was a Parisian artist, who experienced some of the deeper states of meditation and yoga. He later went to Mount Athos, where he became a disciple of St. Silouan. He there experienced uncreated light and the depths of hesychastic contemplation, and was therefore able to speak of comparitive spiritualty by experience.

Mistaking The Light Of The Soul For The Light Of The Uncreated [1]

Wavering In Search Of The Unwavering  [2]

Archimandrite Sophrony Sakharov on Orthodox Wiki  [3]