Ethics: What should we do? What is good? What is normative?

Meta-ethics: What is goodness? What does it mean to be good? What does it mean to be normative?

Aesthetics: What is beautiful?

What may a man do and not be ashamed of it? He may not do nothing surely, for straightaway he is dubbed Dolittle—aye! christens himself first—and reasonably, for he was first to duck. But let him do something, is he the less a Dolittle? Is it actually something done, or not rather something undone?1


  1. Virtue ethics
    1. Introduction
    2. Discussion
    3. Criticism
  2. Deontological ethics
    1. Introduction
    2. Discussion
    3. Criticism
  3. Consequentialism
    1. Introduction
    2. Hedonism
    3. Effective altruism
    4. Criticism
  4. Moral antirealism
    1. Introduction
    2. Is-ought divide
    3. Noncognitivism
    4. Error Theory
    5. Non-objectivism
  5. Moral realism
    1. Introduction
    2. Discussion
  6. Moral naturalism
    1. Introduction
    2. Evolution of morals
    3. Game theory
    4. Science of morality
    5. Nonreductive moral naturalism
  7. Moral non-naturalism
    1. Introduction
    2. Naturalistic fallacy
    3. Moral pluralism
  8. Political philosophy
    1. Capitalism
    2. Marxism
    3. Socialism
  9. Philosophy of law
  10. Economics
    1. Modern portfolio theory
    2. Mutual fund separation theorem
    3. Estimation of covariance matrices
    4. Capital Asset Pricing Model
    5. Efficient-market hypothesis
  11. Free speech
    1. Introduction
    2. Hate speech
    3. Cancel culture
    4. Copyright
  12. Protests and (non-)violence
  13. Feminism
  14. Regret
  15. Compassion
  16. Ecology
  17. Aesthetics
    1. Music theory
    2. Art
    3. Taste
  18. My thoughts
  19. Annotated bibliography
    1. Putnam, H. (2004). The Collapse of the Fact/Value Dichotomy and Other Essays.
    2. Portmore, D. (2011). Commonsense Consequentialism.
    3. More articles to do
  20. Links and encyclopedia articles
    1. SEP
    2. IEP
    3. Wikipedia
    4. Others
    5. Videos
  21. References

Virtue ethics




Deontological ethics



Nothing in the world—indeed nothing even beyond the world—can possibly be conceived which could be called good without qualification except a good will.3


See also:




See also:


Effective altruism


Moral antirealism


Thrasymachus in Plato’s Republic:

Listen then, I say justice is nothing other than the advantage of the stronger.10


Morals and criticism are not so properly objects of the understanding as of taste and sentiment. Beauty, whether moral or natural, is felt, more properly than perceived. Or if we reason concerning it, and endeavour to fix its standard, we regard a new fact, to wit, the general taste of mankind, or some such fact, which may be the object of reasoning and enquiry.11

See also:

Is-ought divide

The end of section 3.1.1 from Hume’s Treatise of Human Nature, “Moral distinctions not derived from reason”:

In every system of morality, which I have hitherto met with, I have always remarked, that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when of a sudden I am surprized to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence. For as this ought, or ought not, expresses some new relation or affirmation, it is necessary that it should be observed and explained; and at the same time that a reason should be given, for what seems altogether inconceivable, how this new relation can be a deduction from others, which are entirely different from it. But as authors do not commonly use this precaution, I shall presume to recommend it to the readers; and am persuaded, that this small attention would subvert all the vulgar systems of morality, and let us see, that the distinction of vice and virtue is not founded merely on the relations of objects, nor is perceived by reason.13

See also:


Error Theory


Figure 1: Main divisions in meta-ethics by Joseph Schmid.

Moral realism



What about someone who believes in beautiful things, but doesn’t believe in the beautiful itself and isn’t able to follow anyone who could lead him to the knowledge of it? Don’t you think he is living in a dream rather than a wakened state? Isn’t this dreaming: whether asleep or awake, to think that a likeness is not a likeness but rather the thing itself that it is like?

I certainly think that someone who does that is dreaming.

But someone who, to take the opposite case, believes in the beautiful itself, can see both it and the things that participate in it and doesn’t believe that the participants are it or that it itself is the participants—he is living in a dream or is he awake?

He’s very much awake.15


Moral naturalism


Stephen R. Brown:

Ethical naturalism: Cognitivist ethical theories in which important ethical norms and evaluations are grounded in natural facts.20

Moral naturalists:

Evolution of morals


Our moral behavior, while more complex than the social behavior of other animals, is similar in that it represents our attempt to manage well in the existing social ecology. … from the perspective of neuroscience and brain evolution, the routine rejection of scientific approaches to moral behavior based on Hume’s warning against deriving ought from is seems unfortunate, especially as the warning is limited to deductive inferences. … The truth seems to be that values rooted in the circuitry for caring—for well-being of self, offspring, mates, kin, and others—shape social reasoning about many issues: conflict resolutions, keeping the peace, defense, trade, resource distribution, and many other aspects of social life in all its vast richness.22

Game theory

Science of morality

See also:

Nonreductive moral naturalism

Moral non-naturalism


Naturalistic fallacy


Still, a gap can be either ditch or abyss. And ditches are not chasms: we may be able to jump over the former though not over the latter. As a matter of fact, we bridge the fact-value gap every time we take action to attain a desirable goal. In other words, action-particularly if well planned-may lead from what is the case to what ought to be the case. In short, action can bridge the logical gap between is and ought, in particular between the real and the rational. This platitude has eluded most if not all value theorists, moral philosophers, and even action theorists—which is witness to their indifference to the real world of action.38

See also:

Moral pluralism

Political philosophy





If only there were evil people somewhere insidiously committing evil deeds, and it were necessary only to separate them from the rest of us and destroy them. But the line dividing good and evil cuts through the heart of every human being. And who is willing to destroy a piece of his own heart?42

Russell in a letter to Wolfgang Paalen (1942):

I think the metaphysics of both Hegel and Marx plain nonsense—Marx’s claim to be ‘science’ is no more justified than Mary Baker Eddy’s. This does not mean that I am opposed to socialism.43



Every one of us has been warmed by fires we did not build. Every one of us has drank from wells we did not dig.45

Philosophy of law


Modern portfolio theory

Mutual fund separation theorem

Estimation of covariance matrices

Capital Asset Pricing Model

Efficient-market hypothesis


Free speech


Hate speech

Cancel culture

Protests and (non-)violence



  1. Women’s suffrage movements (19th and early 20th centuries)
  2. Women’s liberation movement (1960s-1980s)
  3. Third wave (1990s-2012)
  4. Fourth wave (2012-present)

See also:



Make the most of your regrets; never smother your sorrow, but tend and cherish it till it comes to have a separate and integral interest. To regret deeply is to live afresh.69

See also:




Music theory



My thoughts

Debating moral realism with Sean Carroll.

AMA question about naturalism and moral realism.

As a fellow physicist (experimenter with ATLAS) also with an interest in philosophy, I’m really impressed by your efforts to push naturalism and engage philosophers. I fully agree with your materialist and reductionist arguments, supporting that we do understand physics within the everyday regime, and this should inform our metaphysics, philosophy of mind, criticism of pseudoscience, etc. I also like that you emphasize emergence as being an important concept in explaining the nested emergent ontologies in chemistry, biology, economics, etc. My question is why you seem to draw a hard line that ethics and morality cannot be analyzed in the same way. You seem to entertain the criticisms that some people say of “scientism,” that there are some things (like ethics) to which the reductive program of science will not be able to explain. This strikes me as totally inconsistent with the thrust of reductionism and naturalism. I think there are reasonable explanations for why ethics emerge as a set of regularities and good strategies anytime you have groups of people. The constraints on ethics seem to be completely determined by the natural world, including the limits of resources, the needs of our physiology, the laws of probability and game theory, etc. There is no fundamental is/ought divide. “Ought” is a higher descriptive term we give to actions that bring out good situations, for which there are objective metrics, such as health and satisfaction. In this regard, I’m sympathetic with some utilitarians and what Sam Harris seems to be describing in the Moral Landscape. Why do you think emergence from natural laws can introduce new concepts like temperature, phase transitions, supply and demand, but not ethics?

Sean’s reply:

Ryan — Essentially, science is about describing the world, not passing judgment on it. Temperature, phase transitions, and supply and demand are all concepts that helps us understand what happens in the world. Morality is just a completely different endeavor. (Of course you can scientifically study how human beings actually behave — including what they judge to be “moral” — but that’s different than studying how they should behave.) Scientific claims can be judged by experiments, moral claims cannot.

See also:

TODO: Drafting a reply.

I know I’m a consequentialist and a moral realist, but those are broad categories.

There’s no unified or received view of the fact/value, descriptive/normative divide since Hume. But that doesn’t mean there aren’t naturalistic philosophers that deny the dichotomy, i.e., would support the idea roughly that there is a scientific way of discussing and determining what is better. Health and nutrition seem like obvious plausible examples, really any reasoned strategy is normative: it tells one what one should do given what is known. In this sense many naturalists are aligned with game theoretic reasoning about what we should do.

Thought experiment on moral naturalism:

Annotated bibliography

Putnam, H. (2004). The Collapse of the Fact/Value Dichotomy and Other Essays.

  • Putnam (2004)

My thoughts

  • TODO

Portmore, D. (2011). Commonsense Consequentialism.

  • Portmore (2011)

My thoughts

  • TODO

  • TODO







Ayars, A. (2016). Can model-free reinforcement learning explain deontological moral judgments? Cognition, 150, 232–242.
Berlin, I. (1994). A message to the twenty-first century. (Lecture after he received the honorary degree of Doctor of Laws at the University of Toronto).
Bikchandani, S., Riley, J. G., & Hirshleifer, J. (2013). The Analytics of Uncertainty and Information. Cambridge University Press.
Binmore, K. (2011). Natural Justice. Oxford University Press.
Bjornsson, G. & Finlay, S. (2010). Metaethical contextualism defended. Ethics, 121, 7–36.
Black, M. (1964). The gap between "is" and "should". Philosophical Review, 73, 165–181.
Bowling, M., Burch, N., Johanson, M., & Tammelin, O. (2015). Heads-up limit hold’em poker is solved. Science, 347, 145–149.
Brown, S. R. (2008). Moral Virtue and Nature: A defense of ethical naturalism. Continuum.
Bunge, M. (2001). Philosophy in Crisis: The Need for Reconstruction. Prometheus Books.
Chamberlain, G. (1983). A characterization of the distributions that imply mean-variance utility functions. Journal of Economic Theory, 29, 185–201.
Churchland, P. S. (2011). What Neuroscience Tells Us About Morality. Princeton University Press.
Clifford, W. K. (1877). The ethics of belief. Contemporary Review, 29, 289.
Cooper, J. M. & Hutchinson, D. S. (1997). Plato: Complete works. Hackett Publishing.
Coqueret, G. & Milhau, V. (2014). Estimating covariance matrices for portfolio optimization.
Cushman, F. (2013). Action, outcome, and value. Personality and Social Psychology Review, 17, 273–292.
de Waal, F. (1982). Chimpanzee Politics: Power and Sex among Apes. Johns Hopkins University Press.
Elton, E. J., Gruber, M. J., Brown, S. J., & Goetzmann, W. N. (2014). Modern Portfolio Theory and Investment Analysis (9th ed.). Wiley.
Fama, E. (1970). Efficient capital markets: A review of theory and empirical work. Journal of Finance, 25, 383–417.
Goldman, A. H. (1993). Realism about aesthetic properties. The Journal of Aesthetics and Art Criticism, 51, 31–37.
Harris, S. (2010). The Moral Landscape: How science can determine human values. Free Press.
Hayek, F. (1945). The use of knowledge in society. The American Economic Review, 35, 519–530.
Hume, D. (2007). An Enquiry Concerning Human Understanding. (P. Millican, Ed.). Oxford University Press. (Originally published in 1748).
———. (2009). A Treatise of Human Nature. Floating Press. (Originally published in 1740).
Jagannathan, R. & Ma, T. (2003). Risk reduction in large portfolios: Why imposing the wrong constraints helps. The Journal of Finance, 58, 1651–1683.
Joyce, R. (2016). Evolution and moral naturalism. In The Blackwell Companion to Naturalism (pp. 369–385). John Wiley & Sons.
Klocksiem, J. (2019). Against reductive ethical naturalism. Philosophical Studies, 176, 1991–2010.
Ledoit, O. & Wolf, M. (2003). Improved estimation of the covariance matrix of stock returns with an application to portfolio selection. Journal of Empirical Finance, 10, 603–621.
Loeb, D. (2003). Gastronomic realism: A cautionary tale. Journal of Theoretical and Philosophical Psychology, 23, 30–49.
Mackie, J. L. (2007). Ethics: Inventing Right and Wrong. Penguin. (First edition published in 1977).
Mantegna, R. N. (1998). Hierarchical structure in financial markets.
Markowitz, H. M. (1952). Portfolio selection. The Journal of Finance, 7, 77–91.
———. (1959). Portfolio Selection: Efficient Diversification of Investments. Wiley.
———. (2005). Market efficiency: A theoretical distinction and so what? Financial Analysts Journal, 61, 17–30.
Merton, R. C. (1972). An analytic derivation of the efficient portfolio frontier. The Journal of Financial and Quantitative Analysis, 7, 1851–1872.
Moore, G. E. (1988). Principia Ethica. Prometheus Books. (First published in 1903).
Nozick, R. (2013). Anarchy, State, and Utopia. Basic Books. (First edition published in 1974).
Owen, J. & Rabinovitch, R. (1983). On the class of elliptical distributions and their applications to the theory of portfolio choice. Journal of Finance, 38, 745–752.
Parekh, B. (2006). Rethinking Multiculturalism: Cultural Diversity and Political Theory (2nd ed.). Palgrave MacMillan.
Parfit, D. (1984). Reasons and Pearsons. Clarendon Press.
Pettit, P. (1983). The possibility of aesthetic realism. In E. Schaper (Ed.), Pleasure, Preference and Value: Studies in philosophical aesthetics. Cambridge University Press.
Portmore, D. (2011). Commonsense Consequentialism. Oxford University Press.
Prinz, J. (2011). Against empathy. The Southern Journal of Philosophy, 49, 214–233.
Putnam, H. (2004). The Collapse of the Fact/Value Dichotomy and Other Essays. Harvard University Press.
Railton, P. (1986). Moral realism. Philosophical Review, 95, 163–207.
Rawls, J. (1999). A Theory of Justice (2nd ed.). Harvard University Press. (First edition published in 1971).
Rea, M. C. (2006). Naturalism and moral realism. In Knowledge and Reality (pp. 215–241). Dordrecht: Springer.
Richards, J. R. (1980). The Sceptical Feminist: A Philosophical Enquiry. Routledge.
Ross, D. (2005). Economic Theory and Cognitive Science: Microexplanation. Bradford.
Russell, B. (1943). The future of pacifism. The American Scholar, 13, 7–13.
Russell, G. (2020). Logic isn’t normative. Inquiry, 63, 371–388.
———. (2021). How to prove Hume’s law. Journal of Philosophical Logic. (forthcoming).
Scanlon, T. M. (2000). What We Owe to Each Other. Belknap Press of Harvard University Press.
Schurz, G. (1997). The Is/Ought Problem: An Investigation in Philosophical Logic. Dortrecht: Kluwer.
———. (2010a). Comments on Restall, Russell, and Vranas. In C. Pigden (Ed.), Hume, Is and Ought: New Essays (pp. 268–271). Palgrave MacMillan.
———. (2010b). Non-trivial versions of Hume’s is-ought thesis. In C. Pigden (Ed.), Hume, Is and Ought: New Essays (pp. 198–216). Palgrave MacMillan.
Scruton, R. (2018). Why beauty matters. The Monist, 101, 9–16.
Sen, A. (1970). The impossibility of a Paretian Liberal. Journal of Political Economy, 78, 152–157.
———. (2009). The Idea of Justice. Harvard University Press.
Sharpe, W. F. (1963). A simplified model for portfolio analysis. Management Science, 9, 277–293.
———. (1964). Capital asset prices: A theory of market equilibrium under conditions of risk. Journal of Finance, 19, 425–442.
———. (1999). Portfolio Theory and Capital Markets. McGraw-Hill. (Originally published in 1970).
Skarsaune, K. O. (2009). Darwin and moral realism: Survival of the iffiest. Philosophical Studies, 152, 229–243.
Snyder-Hall, R. C. (2010). Third-wave feminism and the defense of "choice". Perspectives on Politics, 8, 255–261.
Solzhenitsyn, A. (1974). The Gulag Archipelago. (T. P. Whitney, Trans.). Harper & Row.
Thomson, J. J. (1971). A defense of abortion. Philosophy & Public Affairs, 1, 47–66.
Wedgwood, R. (2007). The Nature of Normativity. Oxford University Press.

  1. The Journal of Henry David Thoreau, March 5, 1838.↩︎

  2. Rawls (1999).↩︎

  3. Kant, I. (1785). Groundwork of the Metaphysic of Morals, §1.↩︎

  4. Cushman (2013).↩︎

  5. Ayars (2016).↩︎

  6. Portmore (2011).↩︎

  7. Parfit (1984).↩︎

  8. Nozick (2013), p. TODO.↩︎

  9. Joyce, R. (2021). Moral anti-realism, SEP.↩︎

  10. Plato, Republic I 338c, Cooper & Hutchinson (1997), p. 983.↩︎

  11. Hume (2007), Section XII, p. 120.↩︎

  12. Black (1964).↩︎

  13. Hume (2009), p. 715-6.↩︎

  14. Mackie (2007).↩︎

  15. Plato, Republic V 476c, Cooper & Hutchinson (1997), p. 1103.↩︎

  16. Clifford (1877).↩︎

  17. Railton (1986).↩︎

  18. Bjornsson & Finlay (2010).↩︎

  19. Scanlon (2000).↩︎

  20. Brown (2008).↩︎

  21. de Waal (1982).↩︎

  22. Churchland (2011).↩︎

  23. Skarsaune (2009).↩︎

  24. Joyce (2016).↩︎

  25. Binmore (2011).↩︎

  26. Bowling, Burch, Johanson, & Tammelin (2015).↩︎

  27. Harris (2010).↩︎

  28. Putnam (2004).↩︎

  29. Rea (2006).↩︎

  30. Wedgwood (2007), ch. 9.↩︎

  31. Klocksiem (2019).↩︎

  32. Moore (1988).↩︎

  33. Schurz (1997).↩︎

  34. Schurz (2010a).↩︎

  35. Schurz (2010b).↩︎

  36. G. Russell (2020).↩︎

  37. G. Russell (2021).↩︎

  38. Bunge (2001), p. 193.↩︎

  39. Parekh (2006).↩︎

  40. Hayek (1945).↩︎

  41. Nozick (2013).↩︎

  42. Solzhenitsyn (1974), Part 1, Ch. 4.↩︎

  43. Letter from Russell to Wolfgang Paalen, 23 March 1942.↩︎

  44. Berlin (1994).↩︎

  45. Shields, M. (2020). The last night of Mark Shields on the PBS News Hour.↩︎

  46. Markowitz (1952).↩︎

  47. Markowitz (1959).↩︎

  48. Merton (1972).↩︎

  49. Markowitz (2005).↩︎

  50. Elton, Gruber, Brown, & Goetzmann (2014).↩︎

  51. Chamberlain (1983).↩︎

  52. Owen & Rabinovitch (1983).↩︎

  53. Ledoit & Wolf (2003).↩︎

  54. Jagannathan & Ma (2003).↩︎

  55. Coqueret & Milhau (2014).↩︎

  56. Mantegna (1998).↩︎

  57. Sharpe (1963).↩︎

  58. Sharpe (1964).↩︎

  59. Sharpe (1999).↩︎

  60. Fama (1970).↩︎

  61. Sen (1970).↩︎

  62. Sen (2009).↩︎

  63. Bikchandani, Riley, & Hirshleifer (2013).↩︎

  64. Ross (2005).↩︎

  65. B. Russell (1943).↩︎

  66. Thomson (1971).↩︎

  67. Richards (1980).↩︎

  68. Snyder-Hall (2010).↩︎

  69. The Journal of Henry David Thoreau, November 13, 1839. (What the hell did Thoreau know about regret at age 22?)↩︎

  70. Prinz (2011).↩︎

  71. Pettit (1983).↩︎

  72. Scruton (2018).↩︎

  73. Goldman (1993).↩︎

  74. Loeb (2003).↩︎