Weiss mentions here his use of escape clauses as "to all intents
and purposes", "relatively bounded", "relatively constant", "essential" in relation to the issue of the non-existence of wholly autonomous, tightly bounded, systems of any order of magnitude and complexity.
He mentions the emphasis placed by Bertalanffy (1945) on "open systems". True to his concept “of the primacy of continuity and interrelatedness throughout the Universe”, he must consider all systems as "open" - ideally and theoretically. Basically, all systems must be expected to be open somewhere somehow. For practical purposes, we might close them by empirical boundaries, subject to amendment.
Systems - theoretically founded
Having presented the case for the hierarchical organization of living systems in assertive form, Weiss comes to document those assertions in the form of a few illustrative examples, presented in two parts: a brief theoretical one and a more elaborate concrete one dealing with the living cell.
“On the theoretical side, there is a strictly logical test for the
identification of a system. It rests on the nature of the
interrelations between the units conceived of atomistically, through primary abstraction, as isolated, separate and autonomous”.
Weiss then points to his previous discussion of analysis and synthesis (see the erector set analogy). The synthetic insight, explaining things by addition,
would apply only “for those particular cases in which our original primary abstraction has been empirically validated, that is, on the premise that the abstracted entities have actually been proved to be relatively autonomous”. “The fundamental distinction of a system is that this premise definitely does not apply as far as the relations among its constituents are concerned”.
“Let us assume, for instance, a triplet of units, A, B, and C, each of which depends for its very existence upon interactions with, or contributions from, the other two. Then, obviously, we could not achieve a step-wise assembly of this triplet, the way we did before by first joining A to B and then adding C;
for in the absence of C, neither A nor B could have been formed,
existed or survived. In short, the coexistence and co-operation of all three is indispensable for the existence and operation of any one of them.”
Weiss mentions that in empirical studies, processes in living systems present themselves “as just such networks of mutually interdependent tributaries to the integral operation of the whole group”. Examples of systems of this type of "physical wholeness" can be
represented by inorganic analogies. “A self-supporting arch is one
example. One could never close an arch by piling loose stones upon one another because they start to slip off at the curvature. In other words, an arch as a self-supporting structure can only exist in its entirety or not at all.” Human imagination has found ways of building arches piece by piece, by help of cements or of a scaffolding. “But those are contrivances of a living system, the resourceful human brain, enabling a system to be synthesized
from parts, a feat which could never have been accomplished without such help from another system”: System begets system.
This conclusion leads to an example in living systems, namely, “the
reproduction of the macromolecules in the living cell”. Although
commonly referred to as "synthesis", this process is radically
different from what goes under the same name in inorganic chemistry. In the latter, for example, if chlorine and hydrogen are brought together, they will combine to hydrochloric acid, “even if none of the end product hasbeenpresent before”.
“By contrast, the assembly of simple constituents into complex macromolecules in organic systems always requires the presence of a ready-made modelof the product or, at any rate, a template of the same high degree of specificity, to guide the proper order of assemblage”. The best known case is the transcription of genes or sequence of DNA parts into a corresponding sequence of ribonucleic acid (RNA), “the orderly array of which is then translated into a corresponding serial pattern of amino acids in the formation of a protein”.
'Although this copying process of patterns and its various derivative manifestations, such as the highly specific catalysis of further macromolecular species through the enzymatic action of proteins, is often referred to by verbs with the anthropomorphic prefix "self-", these processes are no more "self”-engendered than an arch can be ”self”-building;
for in order to occur at all, they require the specific co-operation of their own terminal products - the enzyme systems which, being indispensable prerequisites for all the links in the metabolic chains, including those for their own formation, thus closethecircleof interdependent component processes to a coherent integrated system. Only the integral totality of such a system could with some justification be called "self-contained", "self-perpetuating", and "self-sustaining".'