I took a sudden passion for Étienne Gilson, for its rigor and for its style, author unknown to me too it seems, wholly writer whose thought comes to you as an inlaid granitic monolith of keys mind like precious crystals. From him, I recommend above all 3 books including this one. Letre Essence and retraces the history of these two concepts (being and gasoline) through philosophical thought. We do not suspect how much the reflection on being could be fruitful and remain so intensely in time, especially in the Middle Ages. The page Parmenides is a little confused. Chapter (staff) on the philosophical vocabulary seemed too much. But the rest is superb, Greeks until Hegel and Kierkegaard, ending with a light but tasty scratch existentialists, finesse and restraint - Reserve believes that is even more evil!