Tag Archives: The Subject-Matter of Ethics

Article Summary: “The Subject-Matter of Ethics” by G.E. Moore

Moore, GE. “The Subject-Matter of Ethics” in Principia Ethica, 1903.


Moore argues that ‘good’ denotes something both simple and indefinable. He does this by refuting the only possible alternatives as to how ‘good’ can be understood: that good is merely equivalent to some natural object, that good is a complex whole which requires analysis, and that good does not exist.

In order to defuse the notion that ‘good’ is merely some natural object, such as pleasure or intelligence, Moore says that equating good with a natural object disallows normative statements. This is because if good is merely pleasure, say, then the only statements that we can produce regarding good become descriptive. We will merely be asserting what ‘is’ the case (that pleasure is good, that this or that thing is pleasurable, i.e., good), rather than what ‘ought’ to be the case. Since normativity is an essential requirement of ethics, we cannot equate good with natural objects. Further, Moore says that when we equate good with natural objects (a move he calls the ‘naturalistic fallacy’),  it becomes impossible to refute such a definition and/or we limit ourselves to a verbal discussion of good. That is to say, when we discuss good, we will merely be discussing how people use the word good, rather than what good actually is.

Moore then disputes in quick succession the notions that good is a complex whole and that good does not exist at all. For any definition we come up with for ‘good,’ Moore asserts, we can ask whether that definition is good or not. It quickly becomes clear, then, that ‘good’ is something separate from any of these definitions. For example, if we define good as that which we desire to desire, then when we ask “Is A good?” we are asking “Is A that which we desire to desire?” It is clear that no one asks such things, and thus ‘good’ cannot be defined as a complex whole.

Meanwhile, Moore is sure that good exists because, so he says, when any lucid person asks a question about what “ought” to be the case, they have a clear, unique object in their mind which is in fact ‘good’ itself. Good is to be understood as a property of things; Moore sees it as uncontroversial that everyone has such a notion in their head. He merely believes it is indefinable (because it is simple).

Logical Outline

Argument One:

  1. Ethics requires normative as well as descriptive statements.*
  2. That which is good is the subject matter of ethics. [53R]
  3. If ‘good’ is equated with any natural object, then there can be only descriptive statements about it and not normative ones. [53R]
  4. Therefore, ‘good’ cannot be equated with any natural objects if we wish to do ethics. [1-3]

Argument Two:

  1. Unless ‘good’ is simple and indefinable, it is either a complex whole or it does not exist at all. [55R]
  2. Good is not a complex whole. [56L]
  3. Good exists. [56R]
  4. It is not the case that good is a complex whole nor that is does not exist at all. [2,3]
  5. Therefore, good is simple and indefinable. [4,1]


Argument One
1. (G = X) → ¬N
2. D ∧ N…Therefore, ¬(G = X)
3. N   (2, SIMP)
4. ¬¬N   (3,DN)
5. ¬(G = X)   (4, 1,MT)

Where G=Good, X=Any natural object, N=There are normative
statements about the good, D=There are descriptive statements about the

Argument Two
1. ¬(Sg ∧ Ig) → (Cg ∨ ¬Eg)
2. ¬Cg
3. Eg…Therefore, (Sg ∧ Ig)
4. ¬Cg ∧ Eg   (2, 3,CONJ)
5. ¬(Cg ∨ ¬Eg)   (4,DeM)
6. ¬¬(Sg ∧ Ig)   (5, 1,MT)
7. (Sg ∧ Ig)   (6,DN)

Where g=Good, S=Simple, I=Indefinable, C=Complex whole, E=Exists.



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