HOME

TheInfoList



OR:

''The Moral Landscape: How Science Can Determine Human Values'' is a 2010 book by
Sam Harris Samuel Benjamin Harris (born April 9, 1967) is an American philosopher, neuroscientist, author, and podcast host. His work touches on a range of topics, including rationality, religion, ethics, free will, neuroscience, meditation, psychedelics ...
, in which he promotes a
science of morality The science of morality may refer to various forms of ethical naturalism grounding morality in rational, empirical consideration of the natural world. It is sometimes framed as using the scientific approach to determine what is right and wrong, ...
and argues that many thinkers have long confused the relationship between morality, facts, and science. He aims to carve a third path between secularists who say morality is subjective ( moral relativists) and religionists who say that morality is dictated by God and scripture. Harris contends that the only viable moral framework is one where "morally good" things pertain to increases in the "well-being of conscious creatures". 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. Challenging the traditional philosophical notion that an "ought" cannot follow from an "is" ( Hume's law), Harris argues that moral questions are best pursued using not just philosophy, but the methods of science, because science can tell us which values lead to human flourishing. It is in this sense that Harris advocates that scientists begin conversations about a normative science of morality. Publication of the book followed Harris's 2009 receipt of a
Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...
in cognitive neuroscience from the
University of California, Los Angeles The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California ...
with a similarly titled thesis: ''The Moral Landscape: How Science Could Determine Human Values''.


Synopsis

Harris's case starts with two premises: "(1) some people have better lives than others, and (2) these differences are related, in some lawful and not entirely arbitrary way, to states of the human brain and to states of the world". The idea is that a person is simply describing material facts (many about their brain) when they describe possible "better" and "worse" lives for themselves. Granting this, Harris says we must conclude that there are facts about which courses of action will allow one to pursue a better life. Harris emphasizes the importance of admitting that such facts exist, because he says this logic also applies to groups of people. He suggests there are better and worse ways for societies to pursue better lives. Just as for an individual, there may be multiple different paths and "peaks" to flourishing for societies—and many more ways to fail. Harris then makes a case that science can usefully define morality using facts about people's well-being. His arguments acknowledge that problems with this scientific definition of morality seem to be problems shared by all science, or reason and words in general. 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. Many of these issues are covered below.


Philosophical case

Although Harris's book discusses the challenges that a
science of morality The science of morality may refer to various forms of ethical naturalism grounding morality in rational, empirical consideration of the natural world. It is sometimes framed as using the scientific approach to determine what is right and wrong, ...
must face, he also mentions that his scientific argument is indeed
philosophical Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some s ...
. Furthermore, he says that this is the case for almost all scientific investigation. He mentions that modern science amounts to careful practice of accepted first philosophical principles like
empiricism In philosophy, empiricism is an epistemological theory that holds that knowledge or justification comes only or primarily from sensory experience. It is one of several views within epistemology, along with rationalism and skepticism. Empiric ...
and
physicalism In philosophy, physicalism is the metaphysical thesis that "everything is physical", that there is "nothing over and above" the physical, or that everything supervenes on the physical. Physicalism is a form of ontological monism—a "one substance ...
.''The Moral Landscape'', pg. 180 He also suggests that science has already very much settled on ''values'' in answering the question "what should I believe, and why should I believe it?". Harris says it should not be surprising that normative ethical sciences are, or would be, similarly founded on bedrock assumptions (
basic norm Basic norm (german: Grundnorm) is a concept in the '' Pure Theory of Law'' created by Hans Kelsen, a jurist and legal philosopher. Kelsen used this word to denote the basic norm, order, or rule that forms an underlying basis for a legal system. ...
s). Harris says: The way he thinks science might engage moral issues draws on various philosophical positions like ethical realism (there are moral facts), and
ethical naturalism Ethical naturalism (also called moral naturalism or naturalistic cognitivistic definism) is the meta-ethical view which claims that: # Ethical sentences express propositions. # Some such propositions are true. # Those propositions are made true ...
(these facts relate to the physical world). Harris says a
science of morality The science of morality may refer to various forms of ethical naturalism grounding morality in rational, empirical consideration of the natural world. It is sometimes framed as using the scientific approach to determine what is right and wrong, ...
may resemble
utilitarianism In ethical philosophy, utilitarianism is a family of normative ethical theories that prescribe actions that maximize happiness and well-being for all affected individuals. Although different varieties of utilitarianism admit different charact ...
, but that the science is, importantly, more open-ended because it involves an evolving definition of well-being. Rather than committing to
reductive materialism Type physicalism (also known as reductive materialism, type identity theory, mind–brain identity theory and identity theory of mind) is a physicalist theory in the philosophy of mind. It asserts that mental events can be grouped into types, a ...
, then, Harris recognizes the arguments of revisionists that psychological definitions themselves are contingent on research and discoveries. Harris adds that any science of morality must consider everything from emotions and thoughts to the actual actions and their consequences. For Harris, moral propositions, and explicit values in general, are concerned with the flourishing of conscious creatures in a society. He argues, "Social morality exists to sustain cooperative social relationships, and morality can be objectively evaluated by that standard." Harris sees some philosophers' talk of strictly ''private'' morality as akin to unproductive discussion of a private, personal physics. "If philosophers want to only talk about some bizarrely unnatural private morality, they are just changing the subject". Harris also discusses how interchangeability of perspective might emerge as an important part of moral reasoning. 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).


Science and moral truths

Harris identifies three projects for science as it relates to morality: (1) explaining why humans do what they do in the name of morality (e.g., traditional
evolutionary psychology Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regards to the ancestral problems they evolv ...
), (2) determining which patterns of thought and behavior humans ''should'' follow (the
science of morality The science of morality may refer to various forms of ethical naturalism grounding morality in rational, empirical consideration of the natural world. It is sometimes framed as using the scientific approach to determine what is right and wrong, ...
), and (3) generally persuading humans to change their ways. Harris says the first project focuses only on describing what is, whereas (2) and (3) focus on what should and could be, respectively. His point is that this second, prescriptive project should be the focus of a
science of morality The science of morality may refer to various forms of ethical naturalism grounding morality in rational, empirical consideration of the natural world. It is sometimes framed as using the scientific approach to determine what is right and wrong, ...
. He also says we should not fear an "
Orwellian "Orwellian" is an adjective describing a situation, idea, or societal condition that George Orwell identified as being destructive to the welfare of a free and open society. It denotes an attitude and a brutal policy of draconian control by pro ...
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. Harris says it is important to delineate project (1) from project (2), lest we commit a moralistic fallacy. He also highlights the importance of distinguishing between (2)—asking what is right—from (3)—trying to change behavior. 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. Harris does not imagine that people, even scientists, have always made the right moral decisions; indeed it is precisely his argument that many of them are wrong about moral facts. This is due to the many real challenges of good science in general, including human cognitive limitations and biases (e.g.,
loss aversion Loss aversion is the tendency to prefer avoiding losses to acquiring equivalent gains. The principle is prominent in the domain of economics. What distinguishes loss aversion from risk aversion is that the utility of a monetary payoff depends o ...
can sway human decisions on important issues like medicine). He mentions the research of Paul Slovic and others to describe just a few of these mental
heuristic A heuristic (; ), or heuristic technique, is any approach to problem solving or self-discovery that employs a practical method that is not guaranteed to be optimal, perfect, or rational, but is nevertheless sufficient for reaching an immediate, ...
s that can keep us from reasoning properly. 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 The Dunning–Kruger effect is a cognitive bias whereby people with low ability, expertise, or experience regarding a certain type of task or area of knowledge tend to overestimate their ability or knowledge. Some researchers also include in th ...
). Harris explains that debates and disagreement are a part of the
scientific method The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific me ...
, and that one side can be wrong. He also says that the debates still available to science illustrate how much work can still be done, and how much conversation must continue.


Harris's positive beliefs

The book is full of issues Harris thinks are far from being morally gray areas. 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". He also suggests it is obvious that loneliness, helplessness, and poverty are bad, but that that is by no means as far as
positive psychology Positive psychology is the scientific study of what makes life most worth living, focusing on both individual and societal well-being. It studies "positive subjective experience, positive individual traits, and positive institutions...it aims t ...
has taken and will take us. In one section, "The illusion of free will", Harris argues that there is a wealth of evidence in psychology (e.g. the
illusion of introspection The introspection illusion is a cognitive bias in which people wrongly think they have direct insight into the origins of their mental states, while treating others' introspections as unreliable. The illusion has been examined in psychological ex ...
) or specifically related to the
neuroscience of free will Neuroscience of free will, a part of neurophilosophy, is the study of topics related to free will ( volition and sense of agency) using neuroscience, and the analysis of how findings from such studies may impact the free will debate. As it ha ...
that suggests that metaphysically free will does not exist. This, he thinks, is intuitive; "trains of thought...convey the apparent reality of choices, freely made. But from a deeper perspective...thoughts simply arise (what else could they do?)".''The Moral Landscape'', pg. 105 He adds, "The illusion of free will is itself an illusion". The implications of free will's nonexistence may be a working determinism, and Harris warns us not to confuse this with
fatalism Fatalism is a family of related philosophical doctrines that stress the subjugation of all events or actions to fate or destiny, and is commonly associated with the consequent attitude of resignation in the face of future events which are thou ...
. One implication of a determined will, Harris says, is that it becomes unreasonable to punish people out of retribution—only behaviour modification and the deterrence of others still seem to be potentially valid reasons to punish.''The Moral Landscape'', pg. 109 This, especially because behaviour modification is a sort of cure for the evil behaviours; Harris provides a thought experiment: Harris acknowledges a hierarchy of moral consideration (e.g., humans are more important than bacteria or mice). He says it follows that there could, in principle, be a species compared to which we are relatively unimportant (although he doubts such a species exists). Harris supports the development of
lie detection Lie detection is an assessment of a verbal statement with the goal to reveal a possible intentional deceit. Lie detection may refer to a cognitive process of detecting deception by evaluating message content as well as non-verbal cues. It also ma ...
technology and believes it would be, on the whole, beneficial for humanity.


Religion: good or bad?

Consistent with Harris's definition of morality, he says we must ask whether religion increases human flourishing today (regardless of whether it increased it in the distant past). He argues that religions may be practiced largely because they fit well with human cognitive tendencies (e.g.
animism Animism (from Latin: ' meaning 'breath, spirit, life') is the belief that objects, places, and creatures all possess a distinct spiritual essence. Potentially, animism perceives all things— animals, plants, rocks, rivers, weather systems, hum ...
). In Harris's view, religion and religious dogma is an impediment to reason, and he takes
Francis Collins Francis Sellers Collins (born April 14, 1950) is an American physician-geneticist who discovered the genes associated with a number of diseases and led the Human Genome Project. He is the former director of the National Institutes of Health (N ...
as an example. Harris criticizes the tactics of secularists like Chris Mooney, who argue that science is not fundamentally (and certainly not superficially) in conflict with religion. Harris sees this as a patronizing attempt to pacify more devout theists. He claims that society can move away from deep dependence on religion just as it has from witchcraft, which he says was once just as deeply ingrained.


Promotion

In advance of publication, four personal and professional acquaintances of the author offered their praise for the book, including biologist and science popularizer
Richard Dawkins Richard Dawkins (born 26 March 1941) is a British evolutionary biologist and author. He is an emeritus fellow of New College, Oxford and was Professor for Public Understanding of Science in the University of Oxford from 1995 to 2008. An ath ...
, novelist
Ian McEwan Ian Russell McEwan, (born 21 June 1948) is an English novelist and screenwriter. In 2008, '' The Times'' featured him on its list of "The 50 greatest British writers since 1945" and '' The Daily Telegraph'' ranked him number 19 in its list of ...
, psycholinguist
Steven Pinker Steven Arthur Pinker (born September 18, 1954) is a Canadian-American cognitive psychologist, psycholinguist, popular science author, and public intellectual. He is an advocate of evolutionary psychology and the computational theory of mind. P ...
, and theoretical physicist
Lawrence Krauss Lawrence Maxwell Krauss (born May 27, 1954) is an American theoretical physicist and cosmologist who previously taught at Arizona State University, Yale University, and Case Western Reserve University. He founded ASU's Origins Project, now ca ...
. They each serve on the Advisory Board of Harris's
Project Reason Samuel Benjamin Harris (born April 9, 1967) is an American philosopher, neuroscientist, author, and podcast host. His work touches on a range of topics, including rationality, religion, ethics, free will, neuroscience, meditation, psychedelics ...
, and their praise appears as
blurb A blurb is a short promotional piece accompanying a piece of creative work. It may be written by the author or publisher or quote praise from others. Blurbs were originally printed on the back or rear dust jacket of a book, and are now also fou ...
s (released by the book's publisher on Harris's website and reproduced on the book's
dust jacket The dust jacket (sometimes book jacket, dust wrapper or dust cover) of a book is the detachable outer cover, usually made of paper and printed with text and illustrations. This outer cover has folded flaps that hold it to the front and back book ...
). Dawkins said, McEwan wrote, "Harris breathes intellectual fire into an ancient debate. Reading this thrilling, audacious book, you feel the ground shifting beneath your feet. Reason has never had a more passionate advocate." Pinker said that Harris offers "a tremendously appealing vision, and one that no thinking person can afford to ignore." 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!" 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."


Reception

''The Moral Landscape'' reached 9th in ''The New York Times'' Best Seller list for Hardcover Non-Fiction in October 2010.


Reviews and criticism

ECSU Associate Professor of Philosophy James W. Diller and Andrew E. Nuzzolilli wrote a generally favorable review in a journal of the
Association for Behavior Analysis International The Association for Behavior Analysis International (ABAI) is a nonprofit organization dedicated to promoting behavior analysis. The organization has over 9,000 members. The group organizes conferences and publishes journals on the topic of app ...
: In his review for Barnes & Noble, Cal State Associate Professor of Philosophy Troy Jollimore wrote that the book "has some good, reasonable, and at times persuasive things to say" to people who are unfamiliar with
moral skepticism Moral skepticism (or moral scepticism in British English) is a class of meta-ethical theories all members of which entail that no one has any moral knowledge. Many moral skeptics also make the stronger, modal claim that moral knowledge is imp ...
, but "has little to say to those people who actually do know what the arguments are, and it will not help others become much better informed." Jollimore also worried that Harris wrongly presents complex issues as having simple solutions.
Kwame Anthony Appiah Kwame Akroma-Ampim Kusi Anthony Appiah ( ; born 8 May 1954) is a philosopher, cultural theorist, and novelist whose interests include political and moral theory, the philosophy of language and mind, and African intellectual history. Appiah was ...
wrote in ''
The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid ...
'' "when
arris In architecture, an arris is the sharp edge formed by the intersection of two surfaces, such as the corner of a masonry unit; the edge of a timber in timber framing; the junction between two planes of plaster or any intersection of divergent a ...
stays closest to neuroscience, he says much that is interesting and important",K.A. Appiah, "Science Knows Best"
''The New York Times'', Oct. 1, 2010
but criticized Harris for failing to articulate "his central claim" and to identify how science has "revealed" that human well-being has an objective component. Appiah argued that Harris "ends up endorsing ... something very like
utilitarianism In ethical philosophy, utilitarianism is a family of normative ethical theories that prescribe actions that maximize happiness and well-being for all affected individuals. Although different varieties of utilitarianism admit different charact ...
, a philosophical position that is now more than two centuries old, ... that faces a battery of familiar problems", which Harris merely "push s... aside." Harris responded to Appiah in the afterword of the paperback version, claiming that all of Appiah's criticisms are addressed in the chapter "Good and Evil". Cognitive anthropologist
Scott Atran Scott Atran (born February 6, 1952) is an American-French cultural anthropologist who is Emeritus Director of Research in Anthropology at the Centre national de la recherche scientifique in Paris, Research Professor at the University of Michiga ...
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 Critiquing the book, Kenan Malik wrote: David Sexton of the London ''
Evening Standard The ''Evening Standard'', formerly ''The Standard'' (1827–1904), also known as the ''London Evening Standard'', is a local free daily newspaper in London, England, published Monday to Friday in tabloid format. In October 2009, after b ...
'' described Harris's claim to provide a science of morality as "the most extraordinarily overweening claim and evidently flawed. Science does not generate its own moral values; it can be used for good or ill and has been. Harris cannot stand outside culture, and the 'better future' he prophesies is itself a cultural projection."
John Horgan John Joseph Horgan (born August 7, 1959) is a Canadian politician who served as the 36th premier of British Columbia from 2017 to 2022, and also as the leader of the British Columbia New Democratic Party from 2014 to 2022. Horgan has been the ...
, journalist for the ''
Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it i ...
'' 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. ... Neuroscience can't even tell me how I can know the big, black, hairy thing on my couch is my dog Merlin. And we're going to trust neuroscience to tell us how we should resolve debates over the morality of abortion, euthanasia and armed intervention in other nations' affairs?"J. Horgan, "Be wary of the righteous rationalist: We should reject Sam Harris's claim that science can be a moral guidepost"
''Scientific American'' blog, Oct. 11, 2010.
Russell Blackford Russell Blackford (born 1954) is an Australian writer, philosopher, and literary critic. Early life and education Blackford was born in Sydney, and grew up in the city of Lake Macquarie, near Newcastle, New South Wales. After graduating wit ...
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. The philosopher
Simon Blackburn Simon Blackburn (born 12 July 1944) is an English academic philosopher known for his work in metaethics, where he defends quasi-realism, and in the philosophy of language; more recently, he has gained a large general audience from his efforts ...
, 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." And H. Allen Orr in ''
The New York Review of Books ''The New York Review of Books'' (or ''NYREV'' or ''NYRB'') is a semi-monthly magazine with articles on literature, culture, economics, science and current affairs. Published in New York City, it is inspired by the idea that the discussion of i ...
'' wrote, "despite Harris's bravado about 'how science can determine human values,' ''The Moral Landscape'' delivers nothing of the kind." Steve Isaacson wrote ''Mining The Moral Landscape: Why Science Does Not (and cannot) Determine Human Values''. Isaacson concludes, "The largest objection to Harris' argument is still Moore's
open-question argument The open-question argument is a philosophical argument put forward by British philosopher G. E. Moore i§13of ''Principia Ethica'' (1903), to refute the equating of the property of goodness with some non-moral property, X, whether natural (e.g. plea ...
. Harris dismisses the argument as a word game easily avoided, but he never explains the game nor how to avoid it. He just ignores it." American novelist
Marilynne Robinson Marilynne Summers Robinson (born November 26, 1943) is an American novelist and essayist. Across her writing career, Robinson has received numerous awards, including the Pulitzer Prize for Fiction in 2005, National Humanities Medal in 2012, and t ...
, writing in ''
The Wall Street Journal ''The Wall Street Journal'' is an American business-focused, international daily newspaper based in New York City, with international editions also available in Chinese and Japanese. The ''Journal'', along with its Asian editions, is published ...
'', 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." At the Moving Naturalism Forward workshop,
Nobel Prize The Nobel Prizes ( ; sv, Nobelpriset ; no, Nobelprisen ) are five separate prizes that, according to Alfred Nobel's will of 1895, are awarded to "those who, during the preceding year, have conferred the greatest benefit to humankind." Alfr ...
-winning physicist
Steven Weinberg Steven Weinberg (; May 3, 1933 – July 23, 2021) was an American theoretical physicist and Nobel laureate in physics for his contributions with Abdus Salam and Sheldon Glashow to the unification of the weak force and electromagnetic interact ...
described how in his youth he had been a utilitarian but had been dissuaded of the notion that "the fundamental principle that guides our actions should be the greatest happiness for the greatest number" by reading
Aldous Huxley Aldous Leonard Huxley (26 July 1894 – 22 November 1963) was an English writer and philosopher. He wrote nearly 50 books, both novels and non-fiction works, as well as wide-ranging essays, narratives, and poems. Born into the prominent Huxley ...
's ''
Brave New World ''Brave New World'' is a Utopian and dystopian fiction#Dystopian fiction, dystopian novel by English author Aldous Huxley, written in 1931 and published in 1932. Largely set in a futuristic World State, whose citizens are environmentally engi ...
''. Weinberg added, "Now, Sam Harris is aware of this kind of counter argument o utilitarianism and says it's not happiness, it's human welfare. Well, as you make things vaguer and vaguer, of course, it becomes harder and harder to say it doesn't fit your own moral feelings, but it also becomes less and less useful as a means of making moral judgements. You could take that to the extreme and make up some nonsense word and say that's the important thing and no one could refute it, but it wouldn't be very helpful. I regard human welfare and the way Sam Harris refers to it as sort of halfway in that direction to absolute nonsense."


Response to critics from Harris

A few months after the book's release, Harris wrote a follow-up at ''
The Huffington Post ''HuffPost'' (formerly ''The Huffington Post'' until 2017 and sometimes abbreviated ''HuffPo'') is an American progressive news website, with localized and international editions. The site offers news, satire, blogs, and original content, and ...
'' responding to his critics. On August 31, 2013, in response to the negative reviews of his book, Harris issued a public challenge for anyone to write an essay of less than 1,000 words rebutting the book's "central argument".The Moral Landscape Challenge : : Sam Harris
/ref> 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. Four hundred twenty-four essays were received by the deadline. On March 11, 2014, Blackford announced the winning essay was by philosophy instructor Ryan Born.''The Moral Landscape Challenge: The Winning Essay''
/ref>


References

{{DEFAULTSORT:Moral Landscape 2010 non-fiction books English-language books Ethics books Philosophy of science literature Contemporary philosophical literature Books by Sam Harris Free Press (publisher) books Thought experiments in ethics Moral psychology books