A circle has a radius and a diameter, but not any one of its points has a diameter.
An atom has a spin property, but no tiger, composed of atoms, has a spin property.
A sample of water freezes at 0 degrees Celsius, but no molecule of H2O freezes.
A brick is red and rectangular, but not any one of its molecules is red and rectangular.
A house has a roof and walls, but no element in the construction of the house has a roof or windows.
A spoken word conveys meaning and elicits a response in a hearer, but not any one of its phonemes conveys meaning or elicits a proportionate response.
In all such cases, while may be the case that the larger, aggregate entity cannot exist without the smaller, composite elements, this does not entail that the former exists because of the latter. The aggregates, thus, enjoy a formal integrity which none of its composite members can bestow upon it.
Indeed, all of the smaller entities are what they are only in reference to their larger aggregate entity's existence. An atom of water is what it is as an atom of water. Even an atom under scientific scrutiny is the atom that it is in connection with the larger aggregate of space cum equipment cum observer. Thus, the aggregate displays as much of a final sovereignty over its members' causal co-relations as it enjoys a formal wholeness that pervades their theoretical content.
Consider Aristotle's claims in Physics II, 9:
As regards what is 'of necessity', we must ask whether the necessity is 'hypothetical', or 'simple' as well. The current [i.e., Empedoclean-materialist] view places what is of necessity in the process of production, just as if one were to suppose that the wall of a house necessarily comes to be because what is heavy is naturally carried downwards and what is light to the top, wherefore the stones and foundations take the lowest place, with earth above because it is lighter, and wood at the top of all as being the lightest. Whereas, though the wall does not come to be without these, it is not due to these, except as its material cause: it comes to be for the sake of sheltering and guarding certain things. Similarly in all other things which involve production for an end; the product cannot come to be without things which have a necessary nature, but it is not due to these (except as its material); it comes to be for an end. For instance, why is a saw such as it is? To effect so-and-so and for the sake of so-and-so. This end, however, cannot be realized unless the saw is made of iron. It is, therefore, necessary for it to be of iron, it we are to have a saw and perform the operation of sawing. What is necessary then, is necessary on a hypothesis; it is not a result necessarily determined by antecedents. Necessity is in the matter, while 'that for the sake of which' is in the definition.
A similar concept plays a role in R. W. Sperry's writings on emergence (which I cite from Timothy O'Connor's essay, "Emergent Properties"). Sperry argues
that the higher-level phenomena in exerting downward control do not disrupt or intervene in the causal relations of the lower-level component activity. Instead, they supervene in a way that leaves the micro interactions, per se, unaltered ("In Defense of Mentalism and Emergent Interaction", Journal of Mind and Behavior 12(2) (1991), p. 230).
Later in the same essay, Sperry elaborates his point by way of considering the molecules in a rolling wheel:
A molecule within the rolling wheel..., though retaining its usual inter-molecular relations within the wheel, is at the same time, from the standpoint of an outside observer, being carried through particular patterns in space and time determined by the over-all properties of the wheel as a whole. There need be no "reconfiguring" of the molecules relative to each other within the wheel itself. However, relative to the rest of the world the result is a major "reconfiguring" of the space-time trajectories of all the components in the wheel's infrastructure. (ibid.)
Sperry's vivid point is that the aggregate object produces empirical changes in the world in a way that, without "violating" the laws of its components, does so to speak outstrip their causal abilities. The wheel can break a vase, whereas its molecules, considered in terms of austere chemical laws, cannot. Indeed, "from a molecule's point of view" there is no such thing as a vase. Therefore it is exceedingly bizarre for reductionists to claim that "our molecules made us x some y" when, in terms of our molecules, there is no y to which x can happen.
For instance, if a reductionist claims that one section of "my" molecules (colloquially called "my arm") caused another section of "my" molecules (colloquially called "my fist") to collide with a section of "your" molecules (colloquially called "your face"), then it should be asked just which molecule or molecules did the hitting and which molecules were mere event freeloaders. If it is objected that the entire "clump" of molecules hit a face-like clump of molecules, this only begs the question of how we delimit (or identify) the guilty clump in molecular terms. In molecular terms, each molecule is doing perfectly what its proper natural laws dictate: clumping with other molecules in a micro-world. Nothing in the law of specific being for a molecule, nor even a clump of molecules, entails that they leap hither and thither from one shocked face to another. Only a being with a higher, enveloping law of specific being--such as a surly human--can do that. Only by already knowing the molecules were metaphysically subservient freeloader's in a human hand's violent action can we correctly specify which molecules were involved in the physical event. Without prior reference to formal substances and their related parts (i.e., humans, hands, faces, etc.), we simply have no reason to describe an arbitrarily selected clump of molecules as "this" or "that" causing "that" or "this". From a wholly reductive, "scientific" point of view, we have no right to stop at the level of molecular clumps forming so-called bodies, since, from the most basic level of analysis, those bodies themselves are but midi-clumps in the macro-swarm of sheer matter-in-motion. Just as for neo-Darwinists, there are not "really" formally distinct species, but only biomass-in-flux, so for the konsequenter reductivist there are no intrinsically intelligible substances (viz., with formal structure cum essential natures), but only undifferentiated Nature simpliciter, or, as I believe J. S. Mill said when parodying Herbert Spencer's evolutionism, one infinite, homogenous It that eternally becomes all things and yet still just remains It.
Obviously, few of us these days can really imagine the world like that. Science, not to mention common-sense phenomenology, unceasingly reveals a world of discrete, dynamic beings co-operating across multiple levels of causation and order. A reductive view of the world is commendable in the same way an expert art historian's critical eye is commendable: by peering in to the tiny details of a work of art, she can discern whether it is a forgery and how it was produced. But if we remain stuck in this posture, without taking a few steps back, we all too easily forget that we are looking at a whole work of art and, moreover, that it is downright beautiful.
It is a mental illusion, inculcated in most moderns and postmoderns, that the micro-view of things "best explains" the phenomena we observe (and cause). But the complementary view--not, you will notice, the competing view--of causation and explanation espoused by Aristotle, Thomas d'Aquino, et al., allows us to break the spell of reductive hypnosis and freely look at the world from a number of complementary perspectives. Specifically, "Aristhomism" enables, nay, liberates us to "be okay with" our amazingly prescient common view of the world, even while acknowledging the micro-structure of reality which exact science illuminates. It is merely a psychological habit in our modernized mind's eye to "zoom in" on atoms and molecules when we "really" want to understand a phenomenon. Meanwhile, if we would, to recall Galileo's simple request, but look through both ends of the metaphysical telescope, we would find a mental freedom to view the world in full, to wit, as a dynamic harmony of contingent but active substances--created finite essences--seeking their fullness of being according to their specific laws of being by means of an "intrawoven" matrix of material, efficient, formal, and final causation. We are conditioned to be reductionistst, but I believe we can, and must, still learn to temper that line of sight with a more so to speak "conductivist" viewpoint.
As an exercise in de-programming, I ask the reader to consider this old tale:
On March 15, 493 in Ravenna, Theodoric invited Odovacar to a dinner, having secretly prepared for assassins to murder Odovacar. The assassins, however, lost their nerve, and Theodoric himself moved in for the kill as Odovacer was seated at the banquet table. With one slash of his sword, Theodoric "lifted his sword and hewed his enemy in twain from the shoulder to the loins," whereupon the former joked that the latter seemed never to have had a bone in his body.
Now, the exercise is this: from which end of the telescope does the story seem more intelligible? From the reductive end that sees a swarm of intrinsically discrete atoms and molecules shifting relative positions, like shadow figures dancing in shadow? Or from the conductive end that sees a violent creature with a name and a sword slicing another man in half, whereupon billions of cells and molecules are sent gushing out? Does it make any more sense to say that a swarm of molecules "were involved in" the naively anthropocentric fictional news story, "Theodoric Goes Halves with Odovacer at Dinner," than it does to say that Theodoric caused billions of molecules belonging to Odovacer to go in wholly unpredictable and grotesquely novel directions?
Hopefully, you see that both accounts make sense of the same event.