It’s taken me over three months to complete this book. Not because it is long, but because it is a book about one of the most important issues of human history. Like most non-fiction, you can’t fly through it; it requires deep thought and much soul-searching. No matter which angle you approach this from, no matter your belief, it requires no less than complete attention. I read a little each night, absorb it, and then move on to the next section/chapter.

This book is a complete history of humanity’s attachment to the search for a moral code, to justify what we believe and why we believe it. From the dawn of written history, we have sought to understand and separate right from wrong and punish those who break collective moral codes. We are not the only species to engage in ethical or moral behaviour, and the process of reward and punishment, but we are the only species to devote so much time to it.

Sometimes that moral code is born out of a utilitarian approach and other times it seems to have little actual benefit to anyone – although it may have done once. Sometimes it is a means of controlling the thoughts and actions of a population while other times it is for the greater good. There is an ethical discussion between collective benefit and individual freedom, for example. This book covers the full spectrum of thoughts on morality – religion and secular ethics, humanism (in both its classical and its modern form), Christianity, Islam, Confucianism, Buddhism, existentialism… even Marxism. It looks at all religions and philosophies describing not just what they believe about right and wrong, but how they changed with each movement within the belief system itself.

If you’re looking for a critical and dispassionate approach to morality, this is certainly the book for you – it’s comprehensive. However, if you read this book looking for validation for your faith or affirmations for your personal moral code, look elsewhere. You are unlikely to find it for the simple reason that this book highlights just how fluid, subjective and changing morality can be with each passing dominating movement. Even within a religion’s, country’s or culture’s collective psyche, what is right and wrong can change depending on the changing outlook of its people.

You’d expect such a broad book with such deep meaning to be heavy, but it’s not. It’s engaging and approachable, providing a great introduction to each period of history, the thinkers who guided morality and ethics and the impact that they had. It’s probably of not much use to philosophy students because it tries to cover some 3,000 years of human history into one medium-sized book. It also treats morality as the global phenomena that it actually is rather than examining it purely from a western-centric point of view or worse – one solely focused on the dominance of the Abrahamic faiths.

It is a great starting point for those wishing to look a little deeper, more than an Idiot’s Guide but not, perhaps, as thorough as an academic textbook. One of the best books of its kind.