Driesch’s definition is as follows: “Entelechy is an agent sui generis, non-material and non-spatial, but acting ‘into’ space.” (Op. cit., p. 204.) Aristotle’s use of the term in this connection is quite different. He uses it, for example, in a static, rather than a dynamic, sense: “The term ‘entelechy,’” he says, “is used in two senses; in one it answers to knowledge, in the other to the exercise of knowledge. Clearly in this case it is analogous to knowledge.” (“Peri Psyches,” Bk. II, c. 1.) Knowledge, however, is only a second or static entelechy. Hence, in order to narrow the sense still further Aristotle refers to the soul as a first entelechy, by which he designates a purely entitive principle, that is, a constituent of being or substance (cf. op. cit. ibidem). The first, or entitive, entelechy, therefore, is to be distinguished from all secondary entelechies, whether of the dynamic order corresponding to kinetic energy or force, or of the static order corresponding to potential energy. Neither is it an agent, because it is only a partial constituent of the total agent, that is, of the total active being or substance. Hence, generally speaking, that which acts (the agent) is not entelechy, but the total composite of entelechy and matter, first entelechy being consubstantial with matter and not a separate existent or being. In fine, according to Aristotelian philosophy, entelechy (that is, “first” or “prime” entelechy) is not an agent nor an energy nor a force. In other words, it is totally removed from the category of efficient or active causes. The second difference between Driesch and Aristotle with respect to the use of the term entelechy lies in the fact that Driesch uses it as a synonym for the soul or vital principle, whereas, according to Aristotle, entelechy is common to the non-living units of inorganic nature as well as the living units (organisms) of the organic world. All vital principles or souls are entelechies, but not all entelechies are vital principles. All material beings or substances, whether living or lifeless, are reducible, in the last analysis, to two consubstantial principles or complementary constituents, namely, entelechy and matter. Entelechy is the binding, type-determining principle, the source of unification and specification, which makes of a given natural unit (such as a molecule or a protozoan) a single and determinate whole. Matter is the determinable and potentially-multiple element, the principle of divisibility and quantification, which can enter indifferently into the composition of this or that natural unit, and which owes its actual unity and specificity to the entelechy which here and now informs it. It is entelechy which makes a chemical element distinct from its isobare, a chemical compound distinct from its isomer, a paramœcium distinct from an amœba, a maple distinct from an oak, and a bear distinct from a tiger.

The molecular entelechy finds expression in what the organic chemist and the stereochemist understand by valence, that is, the static aspect of valence considered as the structural principle of a molecule. Hence it is entelechy which makes a molecule of urea [O:C:(NH2)2] an entirely different substance from its isomer ammonium cyanate [NH4·O·C:N], although the material substrate of each of these molecular units consists of precisely the same number and kinds of atoms. Similarly, it is the atomic entelechy which gives to the isotopes of Strontium chemical properties different from those of the isotopes of Rubidium, although the mass and corpuscular (electronic and protonic) composition of their respective atoms are identical. It is the vital entelechy or soul, which causes a fragment cut from a Stentor to regenerate its specific protoplasmic architecture instead of the type which would be regenerated from a similar fragment cut from another ciliate such as Dileptus.

In all the tridimensional units of nature, both living and non-living, the hylomorphic analysis of Aristotle recognizes an essential dualism of matter and entelechy. Hence it is not in the presence and absence of an entelechy (as Driesch contends) that living organisms differ from inorganic units. The sole difference between these two classes of units is one of autonomy and inertia. The inorganic unit is inert, not in the sense that it is destitute of energy, but in the sense that it is incapable of self-regulation and rigidly dependent upon external factors for the utilization of its own energy-content. The living unit, on the other hand, is endowed with dynamic autonomy. Though dependent, in a general way, upon environmental factors for the energy which it utilizes, nevertheless the determinate form and direction of its activity is not imposed in all its specificity by the aforesaid environmental factors. The living being possesses a certain degree of independence with respect to these external forces. It is autonomous with a special law of immanent finality or reflexive orientation, by which all the elements and energies of the living unit are made to converge upon one and the same central result, namely, the maintenance and development of the organism both in its capacity as an individual and in its capacity as the generative source of its racial type.

The entelechies of the inert units of inorganic nature turn the forces of these units in an outward direction, so that they are incapable of operating upon themselves, of modifying themselves, or of regulating themselves. They are only capable of operating upon other units outside themselves, and in so doing they irreparably externalize their energy-contents. All physicochemical action is transitive or communicable in character, whereas vital action is of the reflexive or immanent type. Mechanical action, for example, is intermolar (i.e. an exchange between large masses of inorganic matter); physical action is intermolecular; chemical action is interatomic; while in radioactive and electrical phenomena we have intercorpuscular action. Hence all the forms of activity native to the inorganic world are reducible to interaction between discontinuous and unequally energized masses or particles. Always it is a case of one mass or particle operating upon another mass or particle distinct from, and spatially external to, itself. The effect or positive change produced by the action is received into another unit distinct from the agent or active unit, which can never become the receptive subject of the effect generated by its own activity. The living being, on the contrary, is capable of operating upon itself, so that what is modified by the action is not outside the agent but within it. The reader does not modify the book, but modifies himself by his reading. The blade of grass can nourish not only a horse, but its very self, whereas a molecule of sodium nitrate is impotent to nourish itself, and can only nourish a subject other than itself, such as the blade of grass. Here the active source and receptive subject of the action is one and the same unit, namely, the living organism, which can operate upon itself in the interest of its own perfection. In chemical synthesis two substances interact to produce a third, but in vital assimilation one substance is incorporated into another without the production of a third. Thus hydrogen unites with oxygen to produce water. But in the case of assimilation the reaction may be expressed thus: Living protoplasm plus external nutriment equals living protoplasm increased in quantity but unchanged in specificity. Addition or subtraction alters the nature of the inorganic unit, but does not change the nature of the living unit. In chemical change, entelechy is the variant and matter is the constant, but in metabolic change, matter is the variant and entelechy the constant. “Living beings,” says Henderson, “preserve, or tend to preserve, an ideal form, while through them flows a steady stream of energy and matter which is ever changing, yet momentarily molded by life; organized, in short.” (“Fitness of the Environment,” 1913, pp. 23, 24.) The living unit maintains its own specific type amid a constant flux of matter and flow of energy. It subjugates the alien substances of the inorganic world, eliminates their mineral entelechies and utilizes their components and energies for its own purposes. The soul or vital entelechy, therefore, is more powerful than the entelechies of inorganic units which it supplants. It turns the forces of living matter inward, so that the living organism becomes capable of self-regulation and of striving for the attainment of self-perfection. It is this reflexive orientation of all energies towards self-perfection that is the unique characteristic of the living being, and not the nature of the energies themselves. The energies by which vital functions are executed are the ordinary physicochemical energies, but it is the vital entelechy or soul which elevates them to a higher plane of efficiency and renders them capable of reflexive or vital action. There is, in short, no such thing as a special vital force. The radical difference between living and non-living units does not consist in the possession or non-possession of an entelechy, nor yet in the peculiar nature of the forces displayed in the execution of vital functions, but solely in the orientation of these forces towards an inner finality.

§ 7. The Definition of Life

Life, then, may be defined as the capacity of reflexive or self-perfective action. In any action, we may distinguish four things: (1) the agent, or source of the action; (2) the activity or internal determination differentiating the agent in the active state from the selfsame agent in the inactive state; (3) the patient or receptive subject; (4) the effect or change produced in the patient by the agent. Let us suppose that a boy named Tom kicks a door. Here Tom is the agent, the muscular contraction in his leg is the activity, the door is the patient or recipient, while the dent produced in the door is the effect or change of which the action is a production. In this action, the effect is produced not in the cause or agent, but in a patient outside of, and distinct from, the agent, and the otherness of cause and effect is consequently complete. Such an action is termed transitive, which is the characteristic type of physicochemical action. In another class of actions, however, (those, namely, that are peculiar to living beings) the otherness of cause and effect is only partial and relative. When the agent becomes ultimately the recipient of the effect or modification wrought by its own activity, that is, when the positive change produced by the action remains within the agent itself, the action is called immanent or reflexive action. Since, however, action and passion are opposites, they can coëxist in the same subject only upon condition that said subject is differentiated into partial otherness, that is, organized into a plurality of distinct and dissimilar parts or components, one of which may act upon another. Hence only the organized unit or organism, which combines unity or continuity of substance with multiplicity and dissimilarity of parts is capable of immanent action. The inorganic unit is capable only of transitive action, whose effect is produced in an exterior subject really distinct from the agent. The living unit or organism, however, is capable of both transitive action and immanent (reflexive) action. In such functions as thought and sensation, the living agent modifies itself and not an exterior patient. In the nutritive or metabolic function the living being perfects itself by assimilating external substances to itself. It develops, organizes, repairs, and multiplies itself, holding its own and perpetuating its type from generation to generation.

Life, accordingly, is the capacity of tending through any form of reflexive action to an ulterior perfection of the agent itself. This capacity of an agent to operate of, and upon, itself for the acquisition of some perfection exceeding its natural equilibrial state is the distinctive attribute of the living being. Left to itself, the inorganic unit tends exclusively to conservation or to loss, never to positive acquisition in excess of equilibrial exigencies; what it acquires it owes exclusively to the action of external factors. The living unit, on the contrary, strives in its vital operations to acquire something for itself, so that what it gets it owes to itself and not (except in a very general sense) to the action of external factors. All the actions of the living unit, both upon itself and upon external matter, result sooner or later in the acquisition on the part of the agent of a positive perfection exceeding and transcending the mere exigencies of equilibration. The inorganic agent, on the contrary, when in the state of tension, tends only to return to the equilibrial state by alienation or expenditure of its energy; otherwise, it tends merely to conserve, by virtue of inertia, the state of rest or motion impressed upon it from without. In the chemical changes of inorganic units, the tendency to loss is even more in evidence. Such changes disrupt the integrity of the inorganic unit and dissipate its energy-content, and the unit cannot be reconstructed and recharged, except at the expense of a more richly endowed inorganic unit. The living organism, however, as we see in the case of the paramæcium undergoing endomixis, is capable of counteracting exhaustion by recharging itself.

The difference between transitive and reflexive action is not an accidental difference of degree, but an essential difference of kind. In reflexive actions, the source of the action and the recipient of the effect or modification produced by it are one and the same substantial unit or being. In transitive actions, the receptive subject of the positive change is an alien unit distinct from the unit, which puts forth the action. Hence a reflexive action is not an action which is less transitive; it is an action which is not at all transitive, but intransitive. The difference, therefore, between the living organism, which is capable of both reflexive and transitive action, and the inorganic unit, which is only capable of transitive action, is radical and essential. This being the case, an evolutionary transition from an inert multimolecule to a reflexively-operating cell or cytode, becomes inconceivable. Evolution might, at the very most, bring about intensifications and combinations of the transitive agencies of the physicochemical world, but never the volte face, which would be necessary to reverse the centrifugal orientation of forces characteristic of the inorganic unit into the centripetal orientation of forces which makes the living unit capable of self-perfective action, self-regulation, and self-renewal. The idea, therefore, of a spontaneous derivation of living units from lifeless colloidal multimolecules must be rejected, not merely because it finds no support in the facts of experience, but also because it is excluded by aprioristic considerations.

§ 8. An Inevitable Corollary

But, if inorganic matter is impotent to vitalize itself by means of its native physicochemical forces, the inevitable alternative is that the initial production of organisms from inorganic matter was due to the action of some supermaterial agency. Certain scientists, like Henderson of Harvard, while admitting the incredibility of abiogenesis, prefer to avoid open conflict with mechanism and materialism by declaring their neutrality. “But while biophysicists like Professor Schäfer,” says Henderson, “follow Spencer in assuming a gradual evolution of the organic from the inorganic, biochemists are more than ever unable to perceive how such a process is possible, and without taking any final stand prefer to let the riddle rest.” (“Fitness of the Environment,” p. 310, footnote.) Not to take a decisive stand on this question, however, is tantamount to making a compromise with what is illogical and unscientific; for both logic and the inductive trend of biological facts are arrayed against the hypothesis of spontaneous generation.