On pp. 30-36 of Principia Ethica, Moore discusses the part-whole relationship called “organic unity.” He describes one meaning attached this term as follows:
But finally (3) the sense which has been most prominent in recent uses of the term “organic whole” is one whereby it asserts the parts of such a whole to have a property which the parts of no whole can possibly have.
It is supposed that just as the whole would not be what it is but for the existence of the parts, so the parts would not be what they are but for the existence of the whole; and this is understood to mean not merely that any particular part could not exist unless the others existed too…, but actually that the part is no distinct object of thought — that the whole, of which it is a part, is in its turn a part of it. … This supposition is self-contradictory…
Well, allow me to retort.
Moore uses a narrow definition of “part” which he understands as “material cause.” When the meaning of this term is restricted in this way, then of course, the proposition “the whole subsists in one of its parts” makes no sense. For example, there is a “deductive a priori” argument that “the whole is no smaller than any of its (material) parts.”
But if A contains and is bigger than B, then for A to be a part of and contained in B would require it to be at the same time smaller than B. Which is absurd.
If, however, we generalize “part” into “cause,” then it is easy to grasp how the entire human body including the arm is an efficient cause of the arm. The efficient cause of a thing answers the question “How does it work?” But it is impossible to understand how an arm works, unless we take into consideration both (a) the fact that the arm is attached to the body and (b) the entire body as a whole. It is the whole body that causes the arm to work. Cut the body off, and it no longer works. Its efficient cause — that which makes it do the things that arms do — is gone; and hence, the effect, i.e., the working arm, disappears along with it.
In this sense, the whole, i.e., the body, is definitely in its part, i.e., the arm. The arm is part / material cause of the body, and the body is part / efficient cause of the arm.
In its capacity as efficient cause, the body sort of “permeates” the arm.
The difference between a mechanical and organic whole, rather obviously, is that in the latter both the whole and the parts are alive, and both not only allow each other to work but to live, as well. Otherwise, mechanical wholes are also efficient causes of their parts.
A car is a complex mechanical whole. Yet it is possible to shut off the engine, disassemble the car into its component parts, then put it back together, and have the car work perfectly well. The human soul may be defined as that aspect of humanity that prevents us from performing a similar procedure on a living person: it is hardly possible to kill a man, carve his body into organs and cells, then slap them back together and reanimate him: anyone who attempted to do that would quickly be assured that zapping the resulting cadaver with a lot of electricity is a poor substitute for the Holy Ghost.
Regarding economics, while Crusoe economics yields important insights, for genuine understanding of this science we need to examine social cooperation among many human beings. Mises, for example, endorses this view as follows:
The market process is coherent and indivisible. It is an indissoluble intertwinement of actions and reactions, of moves and countermoves.
But the insufficiency of our mental abilities enjoins upon us the necessity of dividing it into parts and analyzing each of these parts separately.
In resorting to such artificial cleavages we must never forget that the seemingly autonomous existence of these parts is an imaginary makeshift of our minds. They are only parts, that is, they cannot even be thought of as existing outside the structure of which they are parts.
Take that, Moore!
Society or the economy as wholes are efficient causes of human beings and human actions. Studying a person in isolation from society, therefore, is only of limited, if still definite, interest.