The paper deals with the fundamental problems of Juraj Ciger's philosophical and ethical thinking. Its focus is on Ciger's understanding and explaining of the legacy of the R. Descartes founder of modern philosophy as an enigmatic philosopher. In this context it shows that Descartes was the clue philosopher for Ciger and that in a sense Ciger himself can be seen as an enigmatic philosopher. The author offers an analysis of Ciger's interpretation of Descartes' philosophical conception, which on his opinion was not dualistic, but rather trialistic. The impact of Ciger's thinking on the theoretical and practical (medical) ethics is shown as well.