He then argues that, problems with philosophy of science and reason in general notwithstanding, moral questions have objectively right and wrong answers grounded in empirical facts about what causes people to flourish.

[1] Publication of the book followed Harris's 2009 receipt of a Ph.D. in cognitive neuroscience from the University of California, Los Angeles with a similarly titled thesis: The Moral Landscape: How Science Could Determine Human Values.

Harris also spends some time describing how science might engage nuances and challenges of identifying the best ways for individuals and groups to improve their lives.

Rather than committing to reductive materialism, then, Harris recognizes the arguments of revisionists that psychological definitions themselves are contingent on research and discoveries.

He alludes to an "unpleasant surprise principle", where someone realizes they have been supporting an ineffective moral norm (e.g. reported cases of Jew-hunting Nazis discovering that they themselves were of Jewish descent).

[12] He also says we should not fear an "Orwellian future" with scientists at every door: vital progress in the science of morality could be shared in much the same way as advances in medicine.

He says we must realize that the nuances of human motivation are a challenge in themselves; people often fail to do what they "ought" to do, even to be successfully selfish: there is every reason to believe that discovering what is best for society would not change every member's habits overnight.

[17] Although he mentions that training might temper the influence of these biases, Harris worries about research showing that incompetence and ignorance in a domain leads to confidence (the Dunning–Kruger effect).

For instance, he references one poll that found that 36% of British Muslims think apostates should be put to death for their unbelief, and says that these people are "morally confused".

Harris criticizes the tactics of secularists like Chris Mooney, who argue that science is not fundamentally (and certainly not superficially) in conflict with religion.

[13] In advance of publication, four personal and professional acquaintances of the author offered their praise for the book,[30] including biologist and science popularizer Richard Dawkins, novelist Ian McEwan, psycholinguist Steven Pinker, and theoretical physicist Lawrence Krauss.

"[32] Krauss wrote that Harris "has the rare ability to frame arguments that are not only stimulating, they are downright nourishing, even if you don't always agree with him!

"[32] Krauss predicted that "readers are bound to come away with previously firm convictions about the world challenged, and a vital new awareness about the nature and value of science and reason in our lives.

It explicates the determinants of moral behavior for a popular audience, placing causality in the external environment and in the organism's correlated neurological states.

Cognitive anthropologist Scott Atran criticized Harris for failing to engage with the philosophical literature on ethics and the problems in attempting to scientifically quantify human well-being, noting that Nobel Prize-winner Daniel Kahneman studies what gives Americans pleasure—watching TV, talking to friends, having sex—and what makes them unhappy—commuting, working, looking after their children.

[39]Critiquing the book, Kenan Malik wrote: Imagine a sociologist who wrote about evolutionary theory without discussing the work of Darwin, Fisher, Mayr, Hamilton, Trivers or Dawkins on the grounds that he did not come to his conclusions by reading about biology and because discussing concepts such as "adaptation", "speciation", "homology", "phylogenetics" or "kin selection" would "increase the amount of boredom in the universe".

"[41] John Horgan, journalist for the Scientific American blog and author of The End of Science, wrote, "Harris further shows his arrogance when he claims that neuroscience, his own field, is best positioned to help us achieve a universal morality.

"[42] Russell Blackford wrote, "The Moral Landscape is an ambitious work that will gladden the hearts, and strengthen the spines, of many secular thinkers" but that he nonetheless had "serious reservations" about the book.

[43] The philosopher Simon Blackburn, reviewing the book, described Harris as "a knockabout atheist" who "joins the prodigious ranks of those whose claim to have transcended philosophy is just an instance of their doing it very badly", pointing out that "if Bentham's hedonist is in one brain state and Aristotle's active subject is in another, as no doubt they would be, it is a moral, not an empirical, problem to say which is to be preferred.

"[44] And H. Allen Orr in The New York Review of Books wrote, "despite Harris's bravado about 'how science can determine human values,' The Moral Landscape delivers nothing of the kind.

"[46] American novelist Marilynne Robinson, writing in The Wall Street Journal, asserted that Harris fails to "articulate a positive morality of his own" but, had he done so, would have found himself in the company of the "Unitarians, busily cooperating on schemes to enhance the world's well being, as they have been doing for generations.

Weinberg added, "Now, Sam Harris is aware of this kind of counter argument [to utilitarianism], and says it's not happiness, it's human welfare.

I regard human welfare and the way Sam Harris refers to it as sort of halfway in that direction to absolute nonsense.

[50] The submissions were vetted by Russell Blackford, with the author of the essay judged best to receive $2,000, or $20,000 if they succeeded in changing Harris's mind.