A strange book, which promotes "spiritual hedonism", Dyonisian attitude of "freedom".
It's in a way aimed to atheists in order to shake them out of their delusions, especially puritans, pietists and materialists.
Hamvas advocates indulgence in wine, strong food, cigarettes and "free" women, in order to appreciate life from a direct, participating sense to get away from abstractions. The point is seeing God in everything, so one should indulge in these pleasures of life and commune with God through it.
To me, this is a corruption of real spiritual life, an antithesis of it. A truly spiritual man is not a slave to hedonism and chasing for wordly pleasure. There's no need for intoxication and exotic dishes, since he's equally satisfied and thankful for any food or drink he consumes. He has no wishes for immorality, not because of judgement of society or fear, but because of radiating Essence, which purifies his Being from within. As St. Paul wrote: "When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things."
That being said, I had my phase of enjoyment in food and drink, when I was young(er). Gluttony and crude pleasure-seeking did have some good sides for development of one's personality, but it's highest value is in being able to remember those times and compare them to today's state of being and seeing the pitifulness of that kind of life.
If one had no such experiences, there's a danger of succumbing to them later in life, while already on the spiritual path, God forbid, even while being a teacher to others!
I wanted to rate the book 2 out of 5, but it would be too harsh, it's an interesting book, Hamvas is an erudite and his writing is interesting. I also understand his philosophy, that a "good" man will not get corrupted by indulgence, but for me a spiritually mature man has no real wish for it.
I'd say that the principles of life outlined in the book are not of any use and would be harmful for the overwhelming majority of people.