At the present time, Amazon.com is not listing that it's not just Edwards, but specifically, Jonathan Edwards (1703-1758), the same one that wrote "Sinners in the Hands of an Angry God". Thus, he is strongly classically evangelical, believing in the doctrines of original sin, love for God... and subsequent Christian teachings such as love for enemy, love for neighbor.The summary of the book for those versed in virtue ethics is that Jonathan Edwards comes out as an agape-virtue ethicist. He thinks of the highest virtue of love ("The General nature of true virtue is love", p.85), which he does not name as agape, but that he does describe as unconditional love towards God, and then proceeding from this virtue, the true virtue of love of neighbor.
It's a rather difficult read, and unlike a lot of sermons which have a flow in argument or repeat their points over and over, and wrap up with a conclusion, Edwards more makes multiple stabs at various points.
Virtue, to Edwards, is the beauty of the quality and exercises of the heart, or those actions which proceed from them (p.2), and true virtue most essentially consists in benevolence to being in general (p.3). Thus, virtue most essentially consists in love (that is to say, that true virtue should inspire acts of love, but acts of love may not be representative of true nature), and true beauty is also the individual's harmony to the universe. There is also a distinction between love of complacence (almost similar to 'eros'), which presupposes beauty, and love of benevolence (specifically looking at God's love, which is not limited to things we consider beautiful). Thus, God's love is uncondition, which is linked to His character, exemplifying true virtue. Also, true virtue is not related to love of gratitude or reciprocity.
Agape love is also explained here, as the 'highest good of the object of love,' 'the highest good of all over the good of one,' and 'opposition of evil'. A number of these are further expounded in chapter 1.
"True virtue must chiefly consist in love to God," Jonathan Edwards declares (p.14). And the secondary ground of love is moral excellency. Edwards also links that the love of God supremely is causal (and linked) with loving others, loving one's neighbor. But true goodness is tied into the purpose of glorifying God (p.25). And then morality must be God-focused and then subordinately benevolent (p. 26)
Chapter 3, Edwards talks about primary beauties, such as benevolence, and virtues (or beauties) of justice, wisdom, and secondary beauties such as regularity, order, symmetry, proportion, harmony, etc., as external beauty reflects true spiritual beauty.
It should be noted that Edwards has a few anachronistic terms, such as "self-love" -- which is not narcissism, but it is "love for our own happiness" (p.44) or "love to himself with respect to his private interest" (p.45). Self-love causes us to love those who either help us or promote our interests, and Edwards argues that this could develop a moral sense (of good/bad) (p. 51).
One of Edward's strongest assumptions is that of original sin, that man is not capable of true virtue (i.e., loving God, and thus others) because of original sin, and that anger is not a good illustrator of virtue due to this original sin (depravity of man). He also describes this "true negative moral goodness" (p.91) in all men which also mistake things for true virtue, as well as desire wickedness or do wickedness, or have moral insensibility, or stupidity of conscience. He goes on to say that "all sin has its source from selfishness, or self-love not subordinate to a regard to being in general" (p.92) -- primarily resulting in resentment from God.
Yet, genuine virtues restrain the advance of sin (namely pride and sensuality, p.96).
