Renford Bambrough 
Moral Scepticism and Moral Knowledge [PDF ebook] 

Originally published in 1979, this book shows that a recognition of the rationality of moral judgment and moral action in no way involves us in diminishing our respect for liberty, authenticity, sincerity or integrity. It maintains that the resolution of these issues lies in recognising that the necessary involvement of the emotions in moral judgments and moral choices need not give rise to any hesitation or reluctance to treat moral questions as needing and permitting the use of the resources of human understanding.