A. N. Leontyev 1981

The problem of the origin of sensation

Source: Paul Ballantyne’s site at York University;
“The problem of the origin of sensation” (pp. 7-53). In Problems of the Development of the Mind. (Trans. M. Kopylova) Moscow: Progress Publishers.

[Section] I. The Problem


The origin, i.e. the genesis proper, of the psyche, and its subsequent evolution, are closely related problems. Our general approach to psychic development is, therefore, directly characterised by [i.e., dependent upon] how we theoretically resolve the problem of the psyche’s origin.

There have been many attempts, of course, to give a fundamental answer to this problem. First and foremost there is the answer that can be briefly designated as... ‘anthropsychism’, and which is associated in the history of philosophical thought with... Descartes. Its essence is that the origin of the psyche is linked with the advent of man, and exists only in man. The whole prehistory of the human mind is thus expunged altogether....

Another, opposite answer is given by the doctrine of ‘panpsychism’, i.e., of the universal mental character of nature. Such views were expounded by certain French materialists like Robinet. Fechner, among others famous in psychology, also held such a view.

Between these two extremes, attributing the existence of mind, on the one hand, only to man, and on the other hand recognising mind as a quality of all matter in general, there are also intermediate views, which are much more common. First of all there is the view that could be called ‘biopsychism’, the essence of which is that the psyche is a property not of all matter in general but solely of living matter. Such were the views of Hobbes and of many natural [p. 8] scientists (Claude Bernard, Haeckel, and others). A psychologist who held this view was Wundt.

There is yet another, fourth mode of answering the problem, i.e. that of attributing the psyche not to matter in general, or to all living matter, but solely to those organisms that have a nervous system. This point of view might be called the conception of ‘neuropsychism’. It was advanced by Darwin and Herbert Spencer, and has become very common both in contemporary physiology and among psychologists...

Can any one of these four positions be adopted as a standpoint in general to orient us correctly on the problem of the origin of mind?

It is as alien to consistently materialist science to hold that mind is the privilege only of man as to attribute universal spirituality to matter. Our view is that the psyche -mind- is a property of matter that arises only at its highest stages of development, at the level of organic, living matter. Does that mean, however, that all living matter has some kind of very simple mind, that the transition from inanimate matter to animate [organisms] is at the same time a transition to... sentient matter?

We suggest that this assumption, too, contradicts modern scientific knowledge of the simplest living matter. Mind can only be the product of living matter’s subsequent evolution, and of the subsequent evolution of life itself.

Thus we must also reject the contention that the psyche originates together with living matter and that it is inherent in the whole organic [animate] world.

There remains the last of the views listed, that the origin of mind is [directly] linked with the development of a nervous system in animals. That view, however, also cannot be accepted uncritically.... because it arbitrarily... ignores the point that, although the organ and the function are inseparably interconnected, their link is not at the same time immobile, singular, and fixed once and for all, so that analogous functions can be performed by different organs.

For example, the function that nerve tissue subsequently began to perform was originally carried out by processes taking place in protoplasm without the involvement of [p. 9] nerves. It has been found that in sponges (Stylotella), which have no nerve elements whatsoever, there are true sphincters, whose action is consequently not regulated by nerve apparatuses (M. Parker). We therefore also cannot accept without further... examination (as many contemporary physiologists do) the view that the origin of mind is tied by a direct and unique link with the origin of the nervous system, although there is no doubt about it in the subsequent stages of evolution.

The problem of the origin of the psyche thus cannot be considered resolved, even in its most general form.

This state of affairs naturally led a number of natural scientists to agnostic positions on this issue. In the last quarter of the nineteenth century Emil Dubois-Reymond, one of the most eminent natural scientists of his time, pointed out, in his address in honour of Leibniz (1880), seven unresolved ‘world riddles’ for human science. One of these was the problem of the origin of sensation. The President of the Berlin Academy, where Dubois-Reymond delivered his address, rejected several of the ‘riddles’ outright when summing up the discussion..., but kept three, emphasizing their allegedly real inaccessibility to human knowledge. One of these three was the problem of the original rise of sensations, a question that Haeckel called, not by chance, the ‘central mystery of psychology’.

There is nothing... more foreign to consistently materialist science than the views of agnosticism, even if they are limited to just one area of knowledge. [p. 10]


The first issue facing investigation of the genesis of the psyche is that of the original, initial form of the psychic. In that regard there are two opposing views. According to one the evolution of mental life begins with the development of a ‘hedonic psyche’, i.e. with the birth of a primitive, rudimentary self-consciousness. The latter consists in the organism’s originally still hazy experience of its own states, experience that is positive in conditions of an abundant diet, growth, and multiplication, and negative in conditions of starvation, partial destruction, and the like. These states, which are the prototype of human experiences of appetite, pleasure, or suffering, allegedly constitute the main basis on which various forms of ‘foreseeing’ consciousness, i.e., consciousness that apprehends the surrounding world, are later developed.

This view can be justified theoretically only from the the standpoint of a psycho-vitalist interpretation of evolution, which posits a special force... that operated at first as a purely internal stimulus and only later ‘armed itself’ with external sense organs. We do not consider this view acceptable in modern research that aspires to be rooted in scientific soil, and do not deem it necessary to make a detailed critique of it at this point.

We are compelled, both theoretically and factually, to regard life first and foremost as an interaction between an organism and its environment.

Only through the evolution of this process of external interaction are the organism’s internal relations and states developed; internal sensitivity, which is associated, in its biological significance, with functional co-adaptation of organs, can therefore only be secondary and dependent on ‘protallaxic’ changes (to use Severtsov’s term). On the contrary, it is external sensitivity functionally linked with the reciprocal action of the organism and environment that must be regarded as primary.

We shall thus take sensation, which reflects objective external reality, as the elementary form of the psyche, and treat the problem of the origin of the psyche in this concrete form as the problem of the genesis of a ‘capacity for sensation’ or (what is the same thing) sensitivity proper.

What can serve as the criterion of sensitivity, that is [p. 11] to say, how can we ascertain in general whether a sensation exists, even in its simplest form? The practical criterion is usually subjective. When we want to know if a person is experiencing a particular sensation, we can proceed quite simply, without going into complicated arguments about method, by asking him directly and receiving a clear-cut reply. We can, furthermore, check the answer by putting the same question to enough other people under the same conditions. If each of the persons questioned, or most of them, also admit to having the sensation, then clearly there will be no doubt that this phenomenon will... always arise in these conditions. The matter is quite different, however, when we are faced with the question of animal sensations. We have no possibility of appealing to the animal’s self-observation; we can know nothing about the subjective world either of the simplest organism or even of highly developed animals. The subjective criterion is consequently totally inapplicable here.

Therefore, when we pose the problem of the criterion of sensitivity (capacity for sensation) as the most elementary form of the psyche, we necessarily must pose the task of searching out a strictly objective criterion rather than a subjective one.

But what can serve as an objective criterion of sensitivity? What can indicate to us the presence or absence of a capacity for sensation in a given animal in relation to some particular effect?

Here we must again first consider the [disciplinary] state of this question. Yerkes [1905] pointed to the existence of two main types of objective criterion of sensitivity... supposedly available, to modern zoopsychology. First of all, there were those known as functional criteria, which were criteria, i.e. attributes, of mind residing in the behaviour of animals.

It can be supposed... that any movement is in general a sign of the presence or absence of sensation. When a dog runs to a whistle it is perfectly natural to assume that it hears the whistle, i.e. that it is sensitive to the corresponding sounds.

Thus, when this question is posed in relation to dogs, [p. 12] things are quite clear at first glance; when we transfer it, however, to animals at a lower level of evolution, and pose it in general form, we at once discover that movement no longer means the existence of animal sensation. Mobility is inherent in every animal; if we took it generally as a sign of sensitivity we would have to say that there is sensation as a psychological phenomenon wheresoever we find phenomena of life, and consequently movement, but that directly contradicts the thesis (incontestable for us) that the psyche, even in its simplest form, is not a property of all organic matter [e.g., plants] but is inherent only in its higher forms. We can, however, ... approach... movement itself in a more differentiated way and inquire whether certain forms of it only, and not all movement, may not be the indicator of sensitivity. A limitation like that also does not solve the problem, since we know [even by way of personal introspection] that even very clearly felt effects may not, in general, be associated with overt external movement.

It is possible, furthermore, to consider the function of movements rather than their form the sign of sensitivity. Such, for example, are the attempts of certain members of the biological trend in psychology to consider an organism’s capacity for defensive movements, or the link between its movement and its antecedent states and its experience, as a sign of sensation. The first of these suggestions is untenable because movements of a defensive character cannot be counterposed to other movements that are an expression of the simplest reactivity. It is a property of all living matter to respond somehow to effects, not only to those favourable to the living body but also, it goes without saying, to unfavourable ones. When an amoeba, for instance, extends a pseudopod in response to the spread of acid in the water around it, that movement is undoubtedly protective, but it is hardly any more evidence of the amoeba’s capacity for sensation than the opposite movement of thrusting out a pseudopod to engulf food matter, or the active movements of ‘pursuing’ prey, so vividly described in protozoa by Jennings.

We are thus unable to single out any special functions that could differentiate movements associated with sensation from those not so associated. [p. 13]

....The reason why it is impossible to infer sensation from animal’s motor functions is that we lack objective grounds for distinguishing irritability or excitability on the one hand, which is usually defined as the general property of all living bodies to enter into a state of activity through the effect of external influences, from sensitivity on the other hand, a property which, although it is a certain form of excitability, is, however, a qualitatively unique form. In fact, whenever we try to infer sensation from movement we come right up against the impossibility of establishing whether, in a given case, we are dealing with sensitivity or with an expression of the simple excitability that is inherent in all living matter.

Quite the same difficulty arises when we move from functional criteria (as Yerkes called them) to structural ones, i.e. when we try to infer the existence of sensation not from a function but from an animal’s anatomical organisation. The morphological criterion is even less reliable. The reason [p. 14] for this is, as we have already said, the organs and functions constitute a unity yet are, however, by no means related to each other, either in a fixed or in an unambiguous way....[p. 15] ....[p. 16]....

The impossibility of distinguishing objectively between processes of sensitivity and irritability led nineteenth century physiology to ignore the distinction altogether. The two terms ‘sensitivity’ and ‘irritability’ were therefore often used as synonyms. At the dawn of its [disciplinary] development physiology did, it is true, distinguish between the two concepts... (von Haller’s sensibilitas and irritabilitas).

The need to distinguish between them has again become an important issue for physiology in our day,.... It is no accident that we again find the idea in Orbeli [1938]....

I shall try and use the concept ‘sensitivity’ ... only in those cases when we can say with certainty that the excitation of a particular receptor and its corresponding higher formations is accompanied with the onset of a definite subjective sensation.

...In all other cases, when there is no certainty that the excitation in question is accompanied with some sort of subjective sensation, or cannot be, we shall speak of a phenomenon of irritability and excitability.

The criterion that Orbeli used... is still purely subjective. While a subjective criterion of sensitivity can be used for purposes [p. 17] of research on man, and is useful in practice, it is, to put it bluntly, nonexistent for animals.... From the standpoint of a purely subjective interpretation of sensitivity... it is only one step... to the... [paradoxical] conclusions... drawn at the end of the nineteenth century... (Bethe, Beer, and Uexküll)... that... zoopsychology is in no way a science of the psyche of animals and can never become one.

The [methodological] problem... is thus quite the same in concrete [empirical] investigations as... in ... theoretical views.... It is this lack of an objective and at the same time direct [i.e., explicitly stated] criterion of animal’s sensitivity..., that has led to most theorists in psychology denying outright that the transition from a capacity for irritability to one for sensitivity is a... [suitable subject] for experimental investigation, on the pseudogrounds that excitability and sensitivity are allegedly concepts relating to two fundamentally different spheres of reality: the one... to the material facts of organic nature, the other... to the world of phenomena which are understood either as an expression of a special, spiritual principle or as purely subjective phenomena accompanied with various organic processes and hence exempt from scientific consideration.

In its general form this... [methodologically dualistic approach to the study of psyche] has been shared by almost all post-Cartesian psychology. Even those trends that are [p. 18] opposed to one another in their philosophical leanings take their stand on the same initial premise of... opposing... subjective mental phenomena... [to] the objective content of material vital processes. In some instances this position is expressed in a... divorce of mind from matter or, on the contrary, in attempts to reduce mental processes mechanically to physiological ones, and in other cases to recognition of a preordained ‘parallelism’ or a [merely] idealistically understood ‘interaction’... existing between them....


The hopeless [disciplinary] situation... that has arisen... despite the immense factual material gathered on animal behaviour obliges us from the start to counterpose a... different approach, which follows from a fundamentally different conception of the psyche...

Mind is a property of living, highly organised material bodies that consists in their ability to reflect through their states the reality around them, which exists independently of them. That is the general, materialist definition of mind.... [A]ny attempt to represent the psychic as if linked with matter, yet at the same time belonging to a special spiritual basis, is a departure from scientific [monist] positions. We cannot confine ourselves merely to acknowledging [dualistically] that our notions, concepts, and ideas and the objective reality which is reflected in them, are not the same. That is to stress only one aspect of the [issue]. For psychology, however, it is especially important also [p. 19] to stress another aspect, namely that any reflection of the objective world in psychic phenomena is nothing other than a function of a material, corporeal subject which itself is a [part] of that world, in other words, that the essence of the psychic lies in the world of objective relations and not outside it. The task of scientific psychology is above all to find that way of concretely studying these subjective phenomena that would, figuratively speaking, penetrate beneath their surface and lay bare their objective relations....

How, in fact, and in what direction, should an investigation move in order to penetrate behind the semblance of the ‘pure subjectivity’ of mental phenomena and yet, at the same time, not to lose the object of study -mind itself? Ever since psychology became a science this [methodological] issue has continually arisen at each new, key stage in its [disciplinary] development. Each psychological trend has tried to deal with it in its own way. The multiformity and complexity of these attempts should not, all the same, be exaggerated. They are very limited, despite the show of terms in which they are clothed.

First of all there is the attempt to examine our psychic [p. 20] world... by looking inside... for the laws that express its essence. Can the findings of observations of variable, unclear subjective psychic phenomena lead us, perhaps, through their careful rational elaboration to understanding of the laws and principles governing the ‘little world’ of our consciousness in the same way that observation of twinkling... stars led mankind to discover the laws governing the motion of the ‘big world’, the world of the Universe?

This idea of classical rational psychology has never, of course, been realised, and it never will be. The world of the phenomena of consciousness is not at all like that of the planets. Consciousness cannot be examined in its self-contained being, because there are no independent relations within it.... For that reason any independent ‘physics’ of the phenomena of consciousness, any ‘mathematics of ideas’, any ‘geometry’ or pure ‘logic of spirit’ is impossible....

We can try to discover the phenomena of consciousness by.... mov[ing] from their surface, not to the external world but,... inward in the... literal sense, i.e. to the brain and the physiological [p. 21] processes taking place in it. In this case, too, however, we are threatened with loss of the object of our study. The phenomena and processes which we discover in the brain and other organs of our body are physiological and not psychological ones. The psyche is always linked with them and does not exist apart from them. Yet can we see in them the essence of the psychic?....

Consciousness, thinking, and mind are not reducible in general to [physiological] processes taking place in the brain, and cannot be deduced directly from them.

With this [reductive] approach we thus find independent, external reality on one side of mental phenomena, and the brain and the nervous, physiological processes that take place in it on the other side, i.e., we find in both cases phenomena that are not psychic....[p. 22]....[p. 23]....

In reality the opposition between the subjective and objective [aspects of psyche] is not absolute and a priori. Development generates their opposition, but mutual transitions are preserved between them through the course of development, eliminating their ‘one-sidedness’. We cannot, consequently, limit ourselves to a purely external [dualistic] comparison of subjective and objective data, but must discover and study this profound and concrete process whereby the objective is transformed into the subjective.


What is the real process that links the two poles of the [monistic] opposition of the objective and subjective, and thus determines whether surrounding reality is reflected in the mind of the subject we are testing -human or animal- and what is the exact form that this reflection takes? What, in other words creates the necessity of the mental reflection of objective reality? [p. 24] The answer.... lies in the conditions and requirements of life itself, i.e., in those [reciprocal] processes that actually link man [and animal] with... reality.... [p. 25]....

Thus..., in order to resolve the issue of the origin of mind, we must begin with an analysis of the conditions [of life] that engender it....

Mind arises at a certain stage of the evolution of life not by chance, but of necessity, i.e. naturally. But in what does the necessity of its origin consist? Clearly, if mind is not simply a purely subjective phenomenon, and not just an ‘epiphenomenon’ of objective processes, but a property that has real importance in life, the necessity of its origin is governed by the evolution of life itself. More complex conditions of life require an organism to have the capacity to reflect objective reality in the form of the simplest sensations. The psyche is not simply ‘added’ to the vital functions of organisms, but arises in the course of their development and provides the basis for a qualitatively new, higher form of life – life linked with mind, with a capacity to reflect reality.

This implies that in order to disclose the transition from living matter that still has no psyche to living matter that [p. 26] has one, we have to proceed not from internal subjective states by themselves, separated from the subject’s vital activity, or from behaviour taken in isolation from mind, or merely as that through which mental states and processes are studied, but from the real unity of the subject’s mind and activity, and to study their internal reciprocal connections and transformations.

[Section] II. Hypothesis


.... We have had... to reject the old [dualist] psychology’s traditional subjective approach... and pose [the origin of psyche question] as one of the [monistic] transition from the simplest forms of life, which are not necessarily associated with phenomena of sensitivity, to the more complex forms that are necessarily... connected with... a capacity for sensation, i.e. the simplest embryonic psyche. It is our object to examine these forms of life and the transition existing between them.

Life is a process of special reciprocal action between bodies organised in a special way. What, however, distinguishes the processes of reciprocal action unique to living matter from those of non-living matter?

There is a view of life that every body is a complex physiochemical machine put in action by energy coming from outside. This equating of the living organism with a machine is, however, profoundly false, and contradicts the basic facts characterising life.

Any machine working on thermal, electrical, or chemical energy is a simple transformer [, conduit, or passive consumer,] of this energy, which means that for it to operate, it must receive some quantity of energy from outside and partly convert it into external work... and partly expend it in the wear of its own parts. With the exception of wear and tear, the machine itself, and the material from which it is made, undergoes no changes in connection with its work. A machine’s wear [p. 27] itself, moreover, is only an external consequence of its work and is not.... a necessary essential condition of the [work] processes that takes place in it.

We have a quite different situation in the case of the work of a living organism, which is only possible given permanent changes in the organism itself. When an organism responds to an external effect by motion, the work done by it comes not from the energy of the particular effect, but always from the energy of a partial breakdown or alteration of the structure of its component material particles, associated with a fall in its energy potential, i.e. from the energy of processes of dissimilation. An organism or organic tissue can... respond to an external influence only when it is an energised structure. As the result of the reaction made.... the energy potential of the corresponding tissue... falls until finally the now exhausted tissue ceases to respond at all to the external influence. The matter broken down in... the organism’s work is the material of the organism itself. This means that energy, or energy-liberating matter, coming from outside, which can be utilised by the organism, is not converted into work directly, but is first assimilated by it, i.e. is converted by the activity of the organism... into a regeneration of its own tissues. ‘The dog,’ Claude Bernard [1974] remarked, ‘does not get fat on mutton fat, it makes dog fat.’ This internal work of the organism, the work of forming and restoring its own matter, also constitutes the content of an opposite process, that of assimilation.

The fundamental cycle of the processes performed in an organism can thus be represented in the following scheme: external energy entering the organism in one form or another is converted and assimilated by it. ...[I]t is not sufficient for the organism to be subjected to the appropriate influence while remaining passive; it... must at the same time do some [assimilative] work. This work may be expressed either in internal processes alone or also in external movement, but it must always happen. Even the simplest organism [or cell body] needs to perform some work in connection with assimilation, in the form, for example, of the movement [p. 28] of what is called protoplasmic streaming which carries off matter coming in from the external medium. No process of organic assimilation is... possible outside living active matter. The chloroplast of green plants by which carbon dioxide is assimilated through the energy of sunlight, converts solar radiant energy into chemical energy only when it is incorporated in a living cell that has a certain structure. Isolated chloroplast in a colloidal solution is incapable, apparently, of such a transformation....

The energy process in living organisms is consequently connected with the breakdown and restoration of parts of the organism itself, i.e. always occurs as a process of dissimilation and assimilation. In contrast to an inanimate machine whose parts remain unaltered..., a living organism is in a state of constant self-renewal....

.... The cessation of assimilation is at the same time the cessation of life. When matter ceases to arrive from outside, therefore, as in starvation, assimilation does not cease but now continues through conversion of the organism’s less vital parts into other, more vitally important [p. 29] structures, so that the organism seems now to consume itself... As Chossat’s findings... show, even when higher animals are starving, around half of all the matter composing their organisms can be converted into more vitally important structures, the greatest weight... being in the fatty tissues and blood (93 and 75 percent), and the least in nerve tissue (less than 0.2 percent). This process of ‘self-consumption’ is even more striking in certain lower animals. A living organism is consequently never in a state that would allow it to be compared to a discharged battery....

Whenever we find phenomena of life... we also find... a process of absorption by the organism of substances from the external medium that are then assimilated by it and, on the other hand, a process of discharge of the products of dissimilation by the organism. This two-way process of exchange of substances (metabolism) is the most significant feature of the [qualitatively special features of reciprocal] interaction between living, i.e., protein bodies and the other bodies that are their nutritional medium....

Exchange of substances also exists apart from life, but the outward, formal similarity of the processes must not lead us astray. When, in Rumbler’s famous experiment, a thin, shellac-coated glass thread was drawn into a drop of chloroform and then ejected as soon as it was freed of the shellac coating, that only demonstrated an outward model [i.e., the external features] of the process of organic metabolism.... [p. 30]....

In the organic world we find an opposite relation between the process of interaction and preservation of the interacting bodies. While any inorganic body ceases to be what it was as a result of interaction [e.g., in a chemical reaction, or in the physical weathering of rock by water], the interaction of living bodies with other bodies is,... a necessary condition for their continued existence.... Conversely, cessation or disturbance of the interaction of organic bodies with other bodies around them leads [eventually] to their decomposition and death. [p. 31]

The transition from processes of reciprocal action in the inorganic world to such processes... [by] living bodies... involves a radical change in the fundamental relation.... At the same time, the new relation, which characterises life, does not simply... replace the old one. It becomes established on the basis of this former relation, which is maintained for the individual elements of the living body, which are in a process of continual destruction and renewal. For the living, interacting body remains itself.... precisely because its... particles are decomposing and regenerating again. This means that the new relation... does not simply eliminate the former... but [preserves] it dialectically.

When we consider any process of reciprocal action in the inorganic world..... it is impossible... to tell which is passive (i.e. the body acted on) in a given interaction. The distinction has only a quite arbitrary sense in that inorganic world. When, for example, we describe.... a chemical reaction: it is irrelevant whether we speak of the action of zinc on sulphuric acid, or of the action of sulphuric acid on zinc. In both cases one and the same chemical process is being thought of.... [p. 32]

We find a fundamentally different situation in the case of the reciprocal action of organic bodies. In the interaction between a living protein body and some other body which serves as nutritional matter for it, the relation of the two... will quite clearly be different. The body absorbed is the object of the living body’s action and as such is annihilated....

....This can be put in another way, as follows: the transition from those forms of reciprocal action that are typical of the inorganic world to the forms of interaction inherent in living matter finds expression in the fact of a differentiation into subject on the one hand and object on the other.

From the standpoint of the fundamental path of scientific study of vital processes, this fact of the differentiation of an active living body possessing an independent power to react is one of fundamental significance. We shall therefore have to dwell specially on certain conclusions that follow from it. [p. 33]... [p. 34]... [p. 35]

.... Human life, human ‘subjectivity’, is, of course, a unique life, a unique subjectivity. Man himself creates the conditions of his existence, and does not find them ready made in Nature. But even if we abstract human life from this peculiarity, i.e., speak of life in its universal form, we must maintain the standpoint of recognising the subject’s capacity to be active. For any living being [i.e., the subject], an object is... also an ‘object [assuring?] its life’, an object in relation to which the living creature is not simply passive, but also active, striving or impassioned.

.... For the plant, the sun is not only an object that reveals its (the plant’s) capacity to assimilate carbon dioxide through solar energy, but is also the primary condition of its life.... The plant bends its stem toward the sun, .... [but] with certain internal conditions the branches of the same plant will wilt [adversely] under the sun and its leaves shrivel...

The fundamental change in the relation between the interaction process and the existence of the interacting bodies noted above,... is thus expressed in a change in the relation between a creature and its object. This relation, too, is not immutable, but is an evolving one. It is different in the inorganic world and in the organic [including plants], and it is different again for the animal and for man....

The processes..., therefore, which embody the subject’s specific relations with the objective reality around it, have to be distinguished from... other [p. 36] processes [which do not]....

The necessity of this distinction needs to be noted... because in spite of its obviousness, it is far from always taken into account....

The specific processes that realise some vital, i.e. active relation of the subject to reality we shall term processes of activity [activeness], in distinction to other processes.

We shall also, accordingly, limit the concept of object. It is normally used in a dual sense: in the broadest one as a thing standing in some kind of relation to other things, i.e. as ‘a thing having existence’; and in a narrower sense – as something withstanding (German Gegenstand), resistant (Latin objectum), that to which an act is directed, i.e. as something to which precisely a living creature relates itself as the object of its activity – indifferently as outward or inward activity (e. g. object of nutrition, object of labour, object of meditation, etc.). From now on we shall employ the term object precisely in this narrower, special sense.

Any activity of an organism is directed to some object or other... Consideration of activity therefore requires us to single out and [p. 37] distinguish that which is its real object, i.e. the object of an active relation of the [particular, or particular kind of] organism.

All lower filterable organisms (certain larvae living in water, copepods, all Tunicata, etc.), for example, are capable... of altering their activity in connection with a change in the aqueous medium; in that connection it can sometimes be said with confidence that the change in the organism’s activity is specifically linked with a definite activating property of the medium, for [instance], with a greater or less concentration of nutrients. Imagine, however, that we have artificially altered the medium... of a Daphnia, by putting it into water that lacks its nutrient plankton but contains particles of some neutral inorganic substance; the daphnia would react to this by a slackening of the movements that create a flow of water to its ventral slit. Is the observed slackening of the water flea’s filtering movements a response to the absence of plankton in the water? Or is it, on the contrary, a response to the presence in it of unassimilable particles? Or does it, finally, depend on some other [aspects of the situation] still, not considered by us? Only by answering these questions can we decide precisely what property of the medium is the object of the daphnia’s activity, i.e. with what kind of a relation we are dealing with here.

Thus, the principal ‘unit’ of a vital process is an organism’s activity; the different activities that realise its diverse vital relations with the surrounding reality are essentially determined by their object; we shall therefore differentiate between separate [i.e., qualitatively different] types of activity according to the difference in their objects.


....[p. 38].... It is obvious that the simplest viable organisms have neither specialised organs of absorption nor specialised organs of movement. As for their functions, the main... one that is absolutely essential is what may be called simple irritability, which is expressed in the organism’s capacity to respond by specific processes to some [directly assimilable] influence of vital significance.

This [elementary and pre-psychic] form of the simplest organism’s reciprocal action with the [surrounding] medium is not preserved unaltered in subsequent evolution.

The process of biological evolution, which takes the form of a constant struggle of heredity and adaptability, is expressed in an ever greater complication of the processes that affect the exchange of substances between an organism and its medium (environment). These processes become more complicated, in particular, in the sense that more highly developed organisms prove to be able to maintain their life through an increasing number of the substances and forms of energy assimilated... A complex chain of processes maintaining the life of organisms arises, as well as specialised, interconnected forms of irritability [p. 40] in relation to the appropriate external influences.

In the course of progressive evolution, ... changes of a general type in... reciprocal action... occur. Organism’s activity is qualitatively altered; ... qualitatively new form[s] of interaction... arise.

.... [In the transition from simple irritability to sensitivity proper] organisms become capable of employing... ever newer sources and... properties of the environment... becoming... irritable... in relation to... effects that are not in themselves capable of determining their assimilative activity... A frog, for instance, orients its body in the direction of a faint rustle reaching it... The energy of the sound or the rustling... is not assimilated by the organism...

What... is the vital, biological role of... irritability in relation to influences of this kind? It is that, in responding... to influences that are not in themselves directly, vitally significant.... an animal comes nearer to the possibility of assimilating the matter and energy needed to maintain its life (e.g. to the possibility of capturing or swallowing an insect rustling in the grass...).

The new form of irritability considered above.... [p. 41] .... is determined not by its own relation to the organism’s life but by its objective relation to other properties....

The first and basic assumption of our hypothesis is... that...[this new] function of the processes that mediate the organism’s activity directed to maintaining its life is... the function of sensitivity, i.e. the capacity for sensation....[p. 42]....

Thus we can preliminarily define sensitivity as follows: sensitivity (capacity for sensation) is... nothing other than irritability in relation to that kind of environmental influence that... orients... [the organism]... by performing a signaling function. The necessity for the rise of this [new] form of irritability is that it mediates the organism’s main vital processes that are now taking place in more complicated conditions of the environment.

Processes of sensitivity... arise and become consolidated in the course of biological evolution... only granted... they are caused by properties of the environment that are... biologically significant for animals; otherwise... they would.... be modified or would disappear altogether. They must necessarily... conform to the objective properties of the environment and correctly reflect them in appropriate [biologically justified] connections. In our example of the frog.... the processes induced in it by rustling reflect... its stable link with the movement of insects that serve as the frog’s food.... [p. 43].... [p. 44]....

The transition from primordial irritability to its specific form that we call sensitivity takes place through a process of complication and extension and, on the other hand contraction of organ’s functions that leads to their specialisation as organs of sensitivity.

What, then is the main condition for sensitivity to arise in animals, and for special organs... of sensation to be developed? We can assume that this main determinant... is the transition from life in a uniform medium to life in a more complicated environment... [From the point of view of the organism, this transition is to be understood as one] from [the pre-psychical and immediate assimilation of] unformed sources of life to [the psychically mediated orientation towards] ones formed as [properties of, or, still later,] as things.

When we speak of [the pre-psychic] sources of life [being] unformed as things, we have in mind those that [directly] maintain [a simple] organism’s existence like the chemical substances dissolved in the aqueous medium in which a given organism lives, or the energy of light and heat. A specific feature of this [unformed] kind of life source is that... the environment [is] capable of inducing active [say protoplasmic] processes in an organism [or cell] simply by operating on it by themselves, i.e. directly. [This feature is the hallmark of the pre-psychical stage of simple irritability outlined above and provides the evolutionary basis upon which both sensory psyche and other forms of higher psychical reflection are built].

The environment shaped as things, on the contrary, and physically shaped sources of life, operate (for the organism) not only by... exerting [direct] biological effect on it, but also [by] those properties stably associated with them (like form, colour, etc.)... The formed body, before affecting the organism by its chemical properties (e.g. a food substance), [now] affects the organism by its other properties like bulk, resilience, etc.... [The stage of sensory psyche constitutes the lower limit of]... mediated relations with the environment....[p. 45].... [p. 46].... [p. 47]....

The essential characteristics of activity connected with sensitivity and capacity for [differentiated] sensation are thus the [nonidentity] on the one hand, of the environment’s properties that are reflected and that stimulate the animal’s activity, and those, on the other hand, which, by affecting the animal as a result of its [intermediary psychical] activity... determine.... the maintenance of its existence.

Development of this disparity in the course of.... adaptation to a changing environment.... also leads to a further complication of their [(the organism’s)] reflection of the external reality around them and to a further [qualitative] development of their psyche [see Leontyev, “An outline of the evolution of the psyche,” 1981] .... [p. 48] .... [p. 53]....

Just as with any scientific thesis that is the result of purely theoretical analysis, the fate of our hypothesis [regarding the lower limit and subsequent qualitative developmental stages of the psyche] will be determined by how far it is able to serve as the basis for experimental research that can disprove it or concretise it and develop it further....

Thanks to Paul F. Ballantyne, Ph.D., April, 5, 2005, pballan@comnet.ca