Moore’s description of the principle of organic unity is extremely straightforward; nonetheless, it is a principle that seems to have generally escaped ethical philosophers and ontologists before his time:
- The value of a whole must not be assumed to be the same as the sum of the values of its parts (Principia, § 18).
According to Moore, a moral actor cannot survey the "goodness" inherent in the various parts of a situation, assign a value to each of them, and then generate a sum in order to get an idea of its total value. A moral scenario is a complex assembly of parts, and its total value is often created by the relations between those parts, and not by their individual value. The organic metaphor is thus very appropriate: biological organisms seem to have emergent properties which cannot be found anywhere in their individual parts. For example, a human brain seems to exhibit a capacity for thought when none of its neurons exhibit any such capacity. In the same way, a moral scenario can have a value far greater than the sum of its component parts.
To understand the application of the organic principle to questions of value, it is perhaps best to consider Moore’s primary example, that of a consciousness experiencing a beautiful object. To see how the principle works, a thinker engages in "reflective isolation", the act of isolating a given concept in a kind of null-context and determining its intrinsic value. In our example, we can easily see that per sui, beautiful objects and consciousnesses are not particularly valuable things. They might have some value, but when we consider the total value of a consciousness experiencing a beautiful object, it seems to exceed the simple sum of these values (Principia 18:2).