It has been the persuasion of an immense majority of human beings that sensibility and thought [as distinguished from matter] are, in their own nature, less susceptible of division and decay, and that, when the body is resolved into its elements, the principle which animated it will remain perpetual and unchanged. However, it is probable that what we call thought is not an actual being, but no more than the relation between certain parts of that infinitely varied mass, of which the rest of the universe is composed, and which ceases to exist as soon as those parts change their position with respect to each other. —Percy Bysshe Shelley
What is Life? One dissects a body but finds no life inside. What is Mind? One dissects a brain but finds no mind therein. Are life and mind so much more than the sum of their parts that it is useless to search for them? To answer that, consider this parody of a conversation between a Holist and an ordinary Citizen.
Holist: I'll prove no box can hold a mouse. A box is made by nailing six boards together. But it's obvious that no box can hold a mouse unless it has some ‘mousetightness’ or ‘containment.’ Now, no single board contains any containment, since the mouse can just walk away from it. And if there is no containment in one board, there can't be any in six boards. So the box can have no mousetightness at all. Theoretically, then, the mouse can escape!
Citizen: Amazing. Then what does keep a mouse in a box?
Holist: Oh, simple. Even though it has no real mouse- tightness, a good box can ‘simulate’ it so well that the mouse is fooled and can't figure out how to escape.
What, then, keeps the mouse confined? Of course, it is the way a box prevents motion in all directions, because each board bars escape in a certain direction. The left side keeps the mouse from going left, the right from going right, the top keeps it from leaping out, and so on. The secret of a box is simply in how the boards are arranged to prevent motion in all directions!
That's what containing means. So it's silly to expect any separate board by itself to contain any containment, even though each contributes to the containing. It is like the cards of a straight flush in poker: only the full hand has any value at all.
The same applies to words like life and mind. It is foolish to use these words for describing the smallest components of living things because these words were invented to describe how larger assemblies interact. Like boxing-in, words like living and thinking are useful for describing phenomena that result from certain combinations of relationships. The reason box seems nonmysterious is that everyone understands how the boards of a well-made box interact to prevent motion in any direction. In fact, the word life has already lost most of its mystery — at least for modern biologists, because they understand so many of the important interactions among the chemicals in cells. But mind still holds its mystery — because we still know so little about how mental agents interact to accomplish all the things they do.