FD suffered epletic "fits" (as they were known then). In 'The Idiot', he writes of his experience in the third person.
"He remembered that he always had one minute just before the epleptic fit when suddenly in the midst of sadness, spiritual darkness and oppression, there seemed at moments a flash of light in his brain, and with extraordinary impetus all his vital forces suddenly began working at their highest tension. The sense of life, the consciousness of self, were multiplied ten times at these moments which passed like a flash of lightning. His mind and heart were flooded with extraordinary light... But these moments, these flashes, were only the prelude of that final second in which the fit began."
FD went on to say that regardless of the "abnormalcy" of his disease that those moments were of "the highest form of existence" and "the acme of harmony and beauty". He concludes with a Rumiesque phrase.
"at the very last conscious moment before the fit began, he had time to say to himself clearly and consciously, "Yes, for this moment one might give one's whole life!"