The Philosophy of the Present
Supplementary Essay 1: Empirical Realism
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There are two points of incidence of any act of knowledge: the deduction of what must occur in experience if the idea we entertain is true, and the reconstruction of the world which the acceptance of the idea involves. Thus, in the theory of relativity, the calculation of the apparent positions of stars close to the rim of the eclipsed sun and the agreement of the calculations of the theory with the revolution of the orbit of Mercury are illustrations of the first. Einstein's theory of a curved space-time or Whitehead's doctrine of intersecting time-systems is an illustration of the second. Barring errors of observation, the so-called experimental proofs remain as data under any alternative theory, while the reconstructed world that arises out of the theory is never in its own right definitive. A new theory will reconstruct this as it has reconstructed its predecessor.
It is interesting to note that this difference in the definitive value of data and of theories under which data are organized and from which they gain new meanings is not due to a higher degree of competence in reaching them. The more competently data are isolated and observed the more likely they are to remain as secure elements in the formulation and solution of later problems; but the logical perfection of a theory and its wide applicability have no bearing upon the likelihood of its survival in the presence of new problems. This is clearly evidenced in the attitude of present-day physicists toward Newtonian mechanics. In fact the very perfection and comprehensiveness of an hypothesis lessen its
(94) survival value in the face of fundamental problems. Scientists find themselves in possession of a constantly increasing body of reliable data, while the very character of their research-undertakings calls for a constant reinterpretation of the world within which their research goes on.
What bearing has this upon the scientist's realism, upon his assurance that there is an intelligible world there over against his investigation? Such a phenomenalist as Mach finds his reality in the data, and is or should be ready to recognize new uniformities among them without feeling that his field of reality has changed. He can regard things and the world made of things as mere convenient and subjective orderings of data which can be rearranged without affecting the only reality with which science is concerned. But our constructive scientists are not phenomenalists. Einstein condemns phenomenalism[1] and among theorists such as Eddington, Weyl, Minkowski, or Whitehead we find no phenomenalist. Technicians such as Rutherford, Bohr, Sommerfeld, Planck, or Schroeder, can state their findings only in terms of things and a world of things, however far removed from perceptual experience.
Data are isolated elements in a world of things. Their isolation is overcome in the new world of the scientist's hypothesis, and it is in this world that the reality lies which he is seeking. He cannot stop with the data in his cognitive advance. They belong to a stage in the investigation which comes before the attainment of knowledge. However uncertain he may be of the achievement, his impulse is not satisfied until the data have taken on the form of things in some sort of an ordered whole. These things may be removed from our perceptual experience and lie in a mathematical or logical intuition belonging to the expert only;
(95) but it is a world made up of objects, not of data, to which his hypothesis gives at least a provisional reality not attaching to them as mere data.
A further trait of the scientist's reality is its independence of the observer. This is strikingly illustrated, in the doctrine of relativity, by the geometry of space-time. An absolute independent of the frames of reference of all observers was an inevitable goal of the most fundamental criticism of commonsense spatial and temporal experience. However ready the scientist has been to recognize the perspectivity of all perception, he has never been infected by those scepticisms that have arisen from such recognition in philosophic doctrine. He has recognized far more adequately than the layman the insurmountable obstacles that defend the cognizable world from any complete comprehension by his science; but he has never relegated the object of his knowledge to the creations of his own perceptions and thought. He has always assumed the existence of something independent of his perception, and of the thought with which his research is occupied. It is this independence which underwrites his experiment. But this reality independent of the perception and thought of the observer is not presented in the data of science, apart from the world to which such data belong. These data are perceptual experiences, isolated by the problem within which they appear, and occurring under such exacting conditions that they can be counted upon to be repeated not only in the scientist's own experience but also, under similar conditions, in that of others. In no case would the independent reality be identified with the refined measurement of points on a photographic plate, or with the observations of an astronomer, in so far as these are in contradiction to current doctrine. It is these latter which constitute the data of science. Independent reality belongs either to the world in so far as not affected by the
(96) problem, or to a reconstituted world. The observations are indications of the necessity of reconstitution, and evidences of the legitimacy of an hypothesis by which such reconstitution is undertaken; but in the form of data they cannot belong to a reconstituted world. Such a world is a system of intelligible things whose meanings have wiped out the isolation of the data, and perhaps have removed their import from the perceptual experience within which they occurred. We are thus brought back to the intelligible reality that is the fundamental assumption of the scientist's undertaking. I have already referred to the meaning of the intelligibility of reality in the scientist's quest for knowledge. It is found in the possibility of deducing, from determining conditions of events as given in experience, what the nature of those events must be. There are, then, two assumptions involved in such intelligibility: (1) that events in their passage are determined, although the degree of this determination is not fixed by the assumption; and (2) that in so far as the determining conditions are given, the character of later events is also given. There is, however, a difference between the givenness of the determining conditions and the givenness of the later events. The former is that of the temporal dimension of experience. But while there is in all passage determination-in abstract phraseology the carrying on of relations-there is also the indeterminateness of what occurs. There is always qualitative difference in passage, as well as identity of relation extending through passage. The "what" that is occurring is given in this relational aspect only. In this lies the rationality of all experience, and the source of symbolism. It is here also that we find the fundamental distinction between the objective and subjective phases of experience. The carrying on of relations is objective. The anticipated qualitative "what" that will
(97) occur is subjective. Its locus is mind. Here we find the second sort of givenness-- that which belongs to later events. In so far as the relations in the passage are there in experience they pass in their identity into further events, but the "what" that will occur is only symbolically present. And the indeterminate "what" involves always a possibly new situation with a new complex of relationships. The givenness of later events is then the extension of the structure of relations found in experience, in which the event can be defined only in its relational import, though we imaginatively anticipate with varying degrees of probability its qualitative character. The intelligibility of the world is found in this structure of relations which are there in experience, and in the possibility of following them on beyond the specious present into a future in so far as this future is determined. The data are such emergent events as fail to fit into the accepted structure of relations, and become nodal points from which a new structure of relations arises. They thus are isolated, though they lie within a world which has not been entirely disrupted. It is in their isolation that they are interesting; and while they are defined in terms of objective relations which are not affected, it is in their opposition to previously accepted meanings that they must be presented. A relaturm that hangs in the air without as yet the structure of relations to which it belongs is given in a type of experience which can embody both its inherence in a world that is there and its contradiction of certain characters of that world.[2] The Michelson-Morley findings are an illustration of this type of experience. The interference rings were unchanged, whether the light waves travelled with the motion of the earth or at right angles to it. Motions were simply
(98) there in a world of exact measurement which was the condition of any experiment. But they were in flagrant opposition to the assumption that these waves travelled in an ether unaffected by that motion, occupying the Newtonian space of current physical doctrine. The unquestioned thereness of these rings in their unexpected conflict with the character of the spatial world to which they had belonged expresses the data's independence of certain characters of that experience in so far as they are in conflict with these findings.
There is an old quarrel between rationalism and empiricism which can never be healed as long as either sets out to tell the whole story of reality. Nor is it possible to divide the narrative between them. When rationalism tells the tale, the goal is a Parmenidean identity; when empiricism tells it, reality disappears in phenomenalistic sands. But in fact contingency presupposes a universal necessary order that has been transgressed, and we achieve universal law only when we have triumphed over exceptions. Empiricism presents the ever-recurrent problem with its hard recalcitrant fact; rationalism, the verified theory in which it disappears. For example, the interpretation of things as events causes "things" to disappear in the geometry of a space-time which is the modern edition of the rationalism of Descartes. Neither the Minkowski space-time, nor Whitehead's intersections of an infinite number of time-systems with the ingression of eternal objects, opens the door to any reality in the perceptual findings of research science. For research science, perceptual findings are part of a world whose unquestioned security is the basis for the reality of the exceptional instance from which the problem springs, and for the reliability of the experimental verification of the later hypothesis; yet they have lost the meaning which had belonged to that world but which the exceptional instance has now annulled. The world was implicitly rational up to the
(99) advent of the problem. It is again rational once the problem is solved. The hard facts of the exceptional instance in observation and experiment have a reality independent of that rationality. To say that their reality is found in the faith that the world nevertheless is rational, is to substitute an emotional state for the immediate datum which asserts itself against a rational order and conceivably might maintain itself even in an irrational universe. It is essential to the scientist's method and attitude that he accept his findings just in their contravening of what had been their meaning, and as real in independence of whatever theory is advanced to explain them. Otherwise they would have no probative power. Such instances, with the problems they involve, constitute the contingency of the scientist's world. They are in the nature of the case unpredictable, and they are in the nature of the case real in spite of their non-rationality. It is also true that every consistent hypothesis rules out all later exceptions to its uniformity, or rather that it will be demolished by any exceptional instance. It is therefore no argument against the geometry of space-time that it opens no door to the contingent. No formally rational doctrine can include within itself the repugnant fact. But it is another matter to give such an account of reality as has within it no place for the authority of new scientific findings. The scientist who welcomes facts that fail to accord with his theory must have a place in his doctrine for the experience within which those facts can appear. Nor can we account for the repugnant fact, for the emergent, by relegating it to an experience that is simply that of a mind that has made a mistake or been in error and now corrects it with a true or at least a truer account of reality. The repugnant fact is without doubt an emergent; it has, however, been customary to place its essential novelty in a mental experience, and to deny it to the world that the mind is experiencing.
(100) Thus radiation from black bodies presented facts repugnant to the formulation of light in terms of a wave process. Presumably an hypothesis will be found in which this repugnancy will disappear. Meantime, we do not question the facts, once they have been tested by approved technique. This comes back to pointer-readings; but we are apt to overlook the fact that pointer-readings involve very complex and extensive apparatus together with the physical housing of this apparatus-the whole perceptual world that is not involved in the doctrine of radiation-and that the facts are but parts of that perceptual world. In that world the pointer readings are emergents. From the scientist's standpoint this world is not mental. Is the emergence of the quanta mental? The Einsteinian must answer yes to this question. There can be no novelty in the geometry of an extension in which time is simply one dimension. In our different frames of reference we happen upon events and all the freshness of novelty is in the adventurer. Whitehead does locate the perspective of the organism within the world with which the scientist deals, and undertakes to open the door to contingency by way of alternative patterns of eternal objects which may have ingression into the perspective, or particular intersections of time systems dependent upon the percipient event. But this logical separation of the event-the occurrence from the characters of the event-the "what it is" that takes place-finds no reflection in the scientist's object. The "what the object is" reflects its characters in its occurrence. If there is contingency in the selection of eternal objects, that contingency surely appears in the happening. Not only etymologically but logically contingency attaches itself to occurrence. Yet from the standpoint of Whitehead's doctrine the event is as unalterably located in a space-time as in the Einsteinian doctrine.
The scientist's emergent appears in his observation of the
(101) repugnant fact. Unquestionably in his experience something novel has occurred, and his experience lies within the world. He is then interested in establishing as a fact that what is novel in his experience is also firmly imbedded in an unquestioned perceptual world. In so far as it is novel--e.g., in so far as the radiation of the black body does not conform to the wave theory of radiation-the new fact exists only as his experimental finding, as his perceptual experience, and he must make sure that any other person under like circumstances will have the same perceptual experience. The reality of this experience of his, and of others carrying out the like experiment, in its opposition to current meanings, is the cornerstone of experimental science. The novel fact is no mere sensation of the scientist, nor any mental state, but something that is happening to things that are real. In its repugnancy to a certain structural character of that world it arises only in the experience of this, that and the other individual; but these experiences must nevertheless belong to an unquestioned objective world. It is important to recognize that this world is not made up out of these individual experiences. They lie within this world. If it were made up of such individual experiences it would lose all its reality; whereas in fact it is a court of final appeal-there is no scientific theory that does not seek its decision, and there is no theory that may not be brought before it. It is entirely conceivable that facts repugnant to the current doctrine of relativity may appear, and it is the anticipation of research science that such will be the case.
It is customary to interpret the independence of data as a metaphysical affirmation of a real world independent of all observation and speculation. There is no necessary implication of this in the scientist's methodology. For the metaphysical affirmation is of a reality that is final, while the scientist's procedure and method contemplate no such
(102) finality. On the contrary, they contemplate continued reconstruction in the face of events emerging in ceaseless novelty. The scientist's method and technique are those of research. Unless his metaphysical predisposition leads him to identify the unquestioned thereness of the data with the finality of a world metaphysically independent of all experience, he cannot discover this finality in the data; for their very form moves toward a doctrine that will relieve them of the character of data and merge them in things. It is only in the identity of the relation in passage that he can find a character which could belong to such a final world. But, as Meyerson has pointed out, [3] such a reflection of reality in the identities that scientific method seeks leads only to a Parmenidean solid.
It is of course possible to approach the problem from the standpoint of this relational structure. Modern mathematics and relational logic are outstanding illustrations of this approach. The first step was taken in the Renaissance, in the freeing of the numerical relations of geometrical elements from the forms of perceptual intuition. Descartes' Analytic Geometry not only opened the door to the powerful instrument of analysis, but also freed the qualitative content of the object of observation from the common-sense structure of things. Scientific analysis was then free to attack the problems of physics and chemistry with the instruments of molecules and atoms, which could be defined in terms of the equations of mechanics. justification for the hypothetical constructions this made possible could be found in the logical deductions of the theory when these were put to the test of experiment. It was mathematical analysis that freed the modern mind from Aristotelian metaphysics, by giving men new objects that could be exactly defined in
(103) terms of relational structures and then bringing these structures to the test of observation, through the deduction of their consequences. The profound distinction between the atomic elements of ancient and those of modern thought lies in the exact definition which modern science gives to its ultimate elements in terms of the mathematical account of the proportions they must submit to and of the changes they must undergo. An Aristotelian science could give no definition of the elements of things except the nature of the things as they lay in experience. There was no method open to the thinker except that of the metaphysics of potentiality and realization. Elements could be thought of only in terms of what they were to become. In the atom of Democritus, weight was an ultimate quality which was conceived as a cause of motion and of changes in motion; but the cause had nothing in common with the effect. It was not possible to utilize the analysis of motion into velocities, accelerations and decelerations and then define the weight the dominant character of the atom-in terms of these determinable elements of motion. Weight was one character and the changes it brought about were other characters. The one could not be defined in terms of the other.
But when mass could be defined in terms of inertia and this in terms of the tendency of a body to remain in a state of rest or motion and in terms of the character of the motion in which it is found, it became possible to use the mathematical account of motion to define both the body and any part of it that this analysis rendered accessible to thought and experiment. It is not simply that there arose a new set of concepts for defining things, but that the situations arising from the mathematical analysis involved relational formulations of the objects. Both the inadequacy of the Cartesian mechanical doctrine and the striking success of Newtonian mechanics emphasized the importance of the
(104) new physical objects that had arisen out of a mathematical dynamics. Their indifference to the teleological natures of things in human experience rendered them peculiarly serviceable for fashioning means for new human ends. Newtonian mechanics gave man a control over nature from a source of which Bacon had not dreamed.
Of equal if not of greater importance was the experimental proof which the exact deduction of consequences from the mathematically formulated hypothesis offered to the scientist. Here was a mathesis which instead of withdrawing into a Platonic world of forms came back to a perceptual world that could be submitted to exact measurement, and found here final support. And again and again the development of mathematical theory has provided the structure within which new objects could be defined. Einstein's speculation upon the relations of motion to measurement and its units antedates his realization that the Michelson-Morley findings and the Lorentz transformations presented the data for the doctrine of relativity. Quanta, on the other hand, present perceptual findings defined in terms of current theory, yet contradicting it. The approach to the problem may be from either side: from that of the particular experience that controverts the theory, or from that of the developed relational theory that offers new objects to scientific investigation.
If we ask, then, what is the logical or cognitive value of the scientist's realism, we receive two different answers. The one breaks out of his attitude in seeking the solution of the problems with which his research is occupied. The other appears in his metaphysical interpretation of this attitude. In the first we find that the scientist's assumption of the independence of the world in which are found the data of science and the objects a tested theory reveals over against the observation and speculation of the scientist, refers always to the world in so far as it is not involved in the
(105) problem upon which he is engaged, and in so far as that world is revealed in scientifically competent, undisputed and tested observation and hypothesis. His acceptance of a real world independent of his processes of knowledge is not based upon the finality of the findings of science, either in its data, or in its logically consistent and experimentally tested theories. Although the data of science, when rigorously ascertained, have a much longer life in the history of science than its theories, they are always possibly subject to revision. This conceivable lack of finality does not, however, affect the data's independence of observation and thought within the field of research. The world to which the data belong is independent of the perception and thought which had failed to recognize them, and any conceivable revision of these data will simply find itself in another world of scientific findings. The scientist has no way of presenting the impermanence of his data except in terms of improved technique, and the same is true of the objects into which the data disappear when a theory has been tested and accepted. They are independent only of the perception and thought of a world whose eyes were as yet closed to them.
The elaborate and highly abstruse relativistic theories carry with them the logical finality of any consistent deduction; but their finality in the history of science depends, first, upon their competent formulation of the independent reality, and, second, upon their success in anticipating later events. And the scientist himself expects this doctrine to be reconstructed just as other scientific doctrines have been reconstructed. He is confident that any later theory will assimilate into its relational structure the data of present-day science-in so far as these stand the test of repetition and improved technique-and the logical structure of present-day theories, as relativity has assimilated the logical structure of classical mechanics; but neither his attitude as a
(106) research scientist nor his method anticipates the finality of the doctrine. What calls for emphasis is that the independent reality carries with it no implication of finality.
We have seen that this independent reality, which is an essential part of the scientist's apparatus, breaks out at two points. First, in the scientific datum it is an accredited experience which runs counter to interpretations and meanings that have hitherto had their place in the world within which we have been living: for example, the reflections of radiations of dark bodies in the quantum problem. Or it is a new object, relationally defined, a so-called "conceptual" object, in so far as experimental evidence can be given for its existence: for example, the electron, as evidenced in Millikan's oil-drop experiment, or the alpha-particle in Rutherford's photographs. Here is a reality actually there, standing on its own feet in spite of accepted meanings and doctrines that contravene it. Or, in the second place, it is the reality of a new theory justified by unquestioned logical implications and supported by observations and experiments that fulfill its own prophecies. The spear-point of independence is thus always directed against objects or ideas belonging to the very experience within which the scientific datum, or the new theory, has appeared.
In the perspectives of every-day perceptual experience we give directly or inferentially to the distant object predominantly a visual object-the dimensions it assumes or will assume in a field of common distance and contact experience. The "reality" of a visual object is what one can see himself handling. The visual structure is dominant and even the contact values are ordered in a visual space; but the visual space of immediate proximity to the individual, within which perceptual perspectives have disappeared, lies within a uniform spatial structure coinciding with the grosser structure of contact experience. Contact experience
(107) is the "matter" of common-sense, for it is the goal of that mediate experience within which lie all physical objects, which are in advance of the consummations within the physiological act, and which serve, in organisms that are capable of manipulation, as implements for final consummations. But the spatial structure remains visual because of the superior fineness and exactitude of vision. All distant visual experience is symbolic, in Berkeley's sense; but it is symbolic not of pure contact dimensions, but of those exact dimensions which are ordered in the visual space of our radius of manipulation. Final perceptual reality, however, always presupposes actual or possible manipulatory contact, i.e., it presupposes matter.
The conduct of the individual organism does not necessarily involve more than successful organization of distant stimuli into manipulatory responses under the control of the visual field. That is, appropriate conduct with reference to a distant object may take place without the appearance of physical objects in the experience of the organism. For a physical object in experience is not only a spatially distant stimulus to which we respond. It is a thing which acts or may act upon us. This experience of interaction we undoubtedly have primarily in the pressures located in things which we feel and manipulate. The condition for the experience may be found in the pressure of the hands or of other different parts of the body against each other; but the action upon us of the thing from its inside is a fundamental character that cannot be thus accounted for.
What has just been said has two different possible settings; that of the epistemological problem, and that of the development of the infant's immature experience into that of the community to which he belongs. The epistemologist has assumed that all perceptual experience involves awareness, that is, that all of it carries a cognitive reference to
(108) a something that is not itself, and his problem is found in the attempted identification of this cognitive reference to a world that lies outside of the experience of the individual with the cognition of the individual that attains its goal within experience. The epistemologist starts, therefore, with the immediate experience of the individual and attempts by way of this cognitive reference to reach a world outside of the individual's experience. The biologist and genetic psychologist, on the other hand, start with the world which the individual enters, and undertake to show how this world fashions the experience of the individual, and how he refashions it. The scientist, of course, is working within the setting of the biologist and the psychologist. In his research he must start with a problem that lies within an unquestioned world of observation and experiment. His problem has thrown into doubt certain features of this world but the scientific data are established in what is not shaken. In so far as the perceptual experience of the individual is inadequate-falls short of objectivity-it must be possible to analyse out of it what is not questioned and can be tested by competent observation and experiment. This observation and experiment imply a perceptual world not lying within the problematic area. For the scientist the problem of knowledge does not arise until the exception appears, or until the logical development of the structure of the world brings with it new objects that call for reconstruction.
But while the scientist must observe, measure and experiment within a perceptual world, the hypotheses of recent years, supported and confirmed by experimental tests, have led to the construction of scientific objects which have invaded the field of the perceptual object, and seem to have made of those objects upon and among which his most accurate measurements are carried out, a problem which his scientific doctrine cannot ignore.
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Under the doctrine of the classical mechanics, the perceptual experiences of weight and effort were directly correlated with mass and force. And they were continua which actually or in imagination could be subdivided indefinitely. From the visual-tactual space of what I have termed the manipulatory area, the here and the there, the right and left, and the up and down of perceptual space could be abstracted and there still was left a continuous medium, whose systems of coordinates were subject to arbitrary change of position without affecting the validity of mechanical laws when applied to systems of bodies related to different coordinates. Newtonian absolute space carried with it no incongruity when the physicist made his observations and carried out his experiments in his perceptual world. His own system of coordinates was replaceable by any other without affecting the value of his deductions. Imagination, therefore, carried on indefinitely what the microscope accomplished within its limited range. It presented as perceptual what lay beyond the range of perception, without implying that that which it presented was other than a fractional part of that which was perceptual. Physicists could construct models of their hypotheses that were but the finer anatomy of the perceptual world.
But with the theories of electro-magnetism came an analysis which led to elements which could no longer be fractional parts of perceptual things. Lord Kelvin sought to hold on to them, and stated that he could not understand an hypothesis which he could not present in the form of a model. But the lack of invariance in the Maxwell equations, the transformations of Larmor and Lorentz by which this difficulty was conquered, and Einstein's interpretation of the Lorentz transformations got behind the very structure of the percept- The perceptual thing separates space and time. It is what it is maugré time. And if it is subject
(110) to time's decay, it is the function of science to get back to those permanent elements which persist. The imperishable atoms of Newton possessed contents of mass which were irrelevant to time. In the perceptual world physical things are the preconditions of events. In the electro-magnetic world the ultimate elements of physical things are events, for time has become an essential characteristic of their contents. Velocities determine mass and dimensions. The outcome, as we have already seen, is a space-time within which events are geometrically plotted, and which should in its geometrical configurations swallow up not only inertial and gravitational energy but also that of electromagnetism, if the program which Einstein has presented, after his initial success in dealing with gravitation, is carried through to its completion.
The scientist finds himself, then, in a perceptual world within which he can make carefully devised observations and refined measurements, the reality of which he does not question in the face of the problem that engages his attention. What he does question are the objects of that world within which contradictions or discrepancies have broken out. Abstraction from these questionable characteristics leaves him still with perceptual objects constituting his scientific data, which moreover will be made the test of any hypothesis that he may advance as a solution of his problem. It is the scientific datum in the world to which it belongs which constitutes for him the independent reality, that reality that is independent of any hypothesis. In so far as he recognizes that a problem may break out anywhere in experience, such data may be said to be independent of any object or structure of objects; but such a problem must arise in a world which will present its own unquestioned scientific data. That is, the scientist never approaches the world as a whole. He must cease to be a research scientist
(111) and become a philosopher before the so-called epistemological problem can be his problem.
In the field of classical mechanics his own abstracted space and time could be imaginatively conceived of as indefinitely divisible. They were continua whose fractional parts made up the wholes of this abstracted perceptual space and time. Furthermore there appeared in perceptual experience not only volumes that were continua capable of such divisions, but also contents of pressure and resistance that were also continua capable of like subdivision, and were correlated with the physical concept of mass, both as quantity of matter and as inertia. These contact experiences occupy a critical position in perception, since they present within the manipulatory area what is symbolized in the distance experience. They constitute the "matter" of the physical object promised by our distance experiences. The objects the scientist observes, and the apparatus he handles and with which he makes his most refined measurements, are subject to this test of perceptual reality. The contact experience must answer to the visual experience if the objects and their world are there. The close correlation of mass and motion with the matter of perceptual experience, and that of the continua of the space and time of physical science with those abstracted from perceptual experience, made it possible without friction or incongruity to present the scientific objects of classical mechanics in the perceptual field of the scientist's own scientific data.
I have already referred to the profound revolution in the conception of the physical object which the theories of electro-magnetism and relativity have brought about. The perceptual object must be there in order that it may endure. The perceptual object cannot be an event. Events in the perceptual world presuppose physical things that have locations, and material contents that are irrelevant to time. In
(112) the structure of the perceptual world space and time are inevitably separated. A world of space-time occupied by events is no longer congruous with the perceptual world, and the only correlation between the two is that of logical patterns. The world of the scientist's experimental findings cannot belong to the world to which they refer.
And there is another revolutionary phase in this most modern physical theory. While all of our distance experience-predominantly the world of vision-points to a reality of contact, though this is placed and ordered in a structure in which eye and hand mutually control each other; the universe of relativity is entirely visual, fashioned by the mechanism of light signals. These signals, immediately directed toward physical things, are reflected from one consentient set to another, so that their reality is never found in any moving or resting thing but rather in transformation formulae by which one distance structure may be translated into another; while the ultimate space-time to which they are referred is a texture that is so caught in its own curvature that these distance symbols can only symbolize the logic of symbolization. It is as though the possibility of formulating any set of meanings in terms of any other set of meanings were used to reduce all meanings to the mechanism of translation. Matter transferred to distance experience becomes only a curvature of space-time.
I have already touched upon that character of the physical thing which exhibits itself in its acting upon us and other physical things from within itself, from its inside. This character does not appear in the scientist's account of physical things. His statement of inertia as the tendency of a body to remain in the state of rest or motion in which it is found, and of force as that which is the cause of such a state, is always in terms of velocities, accelerations, decelerations, and their ratios to each other. It never deals with
(113) the inside of a body but only with the outside which the analysis of the body reveals.
It is a matter of course that the things involved in the observation of the scientist, and the apparatus of his laboratory and experiment are not part of the uncertain field of his problem, and that they have a reality independent of the solution of the problem. Otherwise the problem could never be solved. For example, the actual observations of the position of the stars about the eclipsed sun upon the negatives and the apparatus by which these positions were measured to high degrees of accuracy, unquestionably had a reality to the scientist upon which he depended for his judgment of Einstein's hypothesis. His ultimate reality is found in these carefully devised observations and experiments, and the things there present do not fall under doubt at least until a new problem arises which may involve these very things and the scientist's experience of them. Then, however, he approaches the new problem with a set of equally carefully devised observations and experiments and the unquestioned things which these involve.
It is also true that at the other end of his undertaking when he has assured himself of the viability of his hypothesis, and has perhaps stated it with the finality of the geometry of a Minkowski space-time, this finality in form has no place in his scientific attitude. He is as ready to find a problem within this system as elsewhere in the universe. His finality of statement is logical, that is, it is an affirmation that the hypothesis has been brought into consistent relation to all other pertinent findings in the world as it exists for us. For the moment it meets the demands of what we call the facts, as for example the Newtonian mechanics did for two centuries. Both the factual setting of his problem and the successful dénouement of his investigation have in the scientist's world a reality that belongs
(114) to the present, without the slightest prejudgment as to their reality in a later present. It is only when he philosophizes that the relation of these presents to each other becomes a problem. It is not and cannot be a scientific problem, for it could neither be stated nor solved by an experimental method.
If we recur to the reality of the data in the scientist's procedure, we recognize, as I have already noted, that the data have in one sense a longer period than the objects in terms of which they are stated. In the case of photographs of the positions of the stars about the rim of the eclipsed sun, these positions are stated in terms of the changes in chemical structures on the plate. The nature of these chemical structures, and what takes place under exposure to light, will probably change with the development of physical science; but the relative positions of these spots on the plate will remain unaffected by the different nature of the plate as an object. In the same fashion relative positions of the stars and planets can be traced in reports of the observations of Mesopotamian astrologers, in the catalogues of Grecian astronomers, in the recorded observations of Tycho Brahe, and in those of Copernican astronomers. The objects these various watchers of the sky saw were profoundly different, but it is possible to identify in all these records the same relative positions. It would, however, be a mistake to assume that the scientist could observe simply relative positions, or that in the world of reality by which he tests hypotheses such abstractions can have an independent existence. They are abstractions from things and have reality only in the concretion of these things. The scientist may or may not be uncertain of the nature of the stars, but if his uncertainty were resolved, the stars would be objects in his perceptual world whose positions he would be recording, though the stars will presumably have another
(115) nature for later astronomers. Furthermore even in his uncertainty he must be observing unquestioned perceptual objects-distant spots of light and photographic plates. A world cannot be constructed from scientific data that have been abstracted from the world within which the problem arises. It is also true that in testing the logical consistency of his theory the scientist carries his problem back, at least presumptively, into the structure of those perceptual objects that his problem does not affect, but if such objects lie outside the problem, any inconsistency militates against the theory, not against the reality of the objects.
Now the import of this character of the scientist's method is, as Professor Dewey has long since insisted, that the knowledge-process lies inside of experience, and that the so-called percepts that have not fallen under the doubt knowledge seeks to resolve are simply there, and are affected with no cognitive character. We are not aware of objects about us, except as we seek to reassure ourselves of their existence, their qualities and their meanings; though any object may fall under suspicion and so become an assured object of knowledge. We must be able, for logical and methodological purposes, to state things which are simply there in terms of what we do find in our cognitive adventures.
I will not argue at length Professor Dewey's analysis of cognition, since I am not likely to better his account of it, nor make it more convincing to those whom he has not convinced. I should, however, like to emphasize one feature of this experience which is called perception even when it is applied to what is simply there apart from any attitude of awareness on the part of the so-called percipients. This feature is that of the distance-character of all our perceptual objects. As I have already indicated, this experience is one which is dominated by the head and its neural inheritance.
(116) The physical thing has arisen in experience through the direct control of our conduct toward it in so far as it is related to our organisms by the distance senses lodged in the head, when this relation through the distance-senses calls out in advance and controls manipulatory reactions toward the distant object we are seeking or avoiding. The perceptual object answers to a collapsed act, and if we are in doubt as to the reality of what we see or hear, we must carry the act out to the point of actual contact. The doubting Thomas can be convinced only by his hand. Even tactual illusion can only be dissipated by other contacts. The world that stretches away from our manipulatory area, especially in its perspective characters, is most readily thrown into the cognitive field, though this never concerns more than certain features of the world. There is always a world of perceptual reality there which is the basis for our investigation. It is easy therefore for the psychologist and the epistemologist with his penny to generalize this attitude and attach awareness to all perceptual experience. The answer to him is to be found in the location of his doubt and the fashion in which he dispels it.
We cannot, of course, go back of the immediate experience of handling or seeing an object. But we can state the conditions under which the object of our manipulation and sight is there. These conditions include not only the structure of the physical world in which the objects are found, but also the organism which is related to it and to them. In this sense we can follow out the reflected light as it travels to the retina and the passage of the nervous excitation as it travels along the optic nerve to the central tracts; and in the same fashion we can follow out the excitation of the nerves which pass from the skin, muscles and joints in our handling of the object.
But it is evident that this analysis takes place within a
(117) world of things not thus analysed; for the objects about us are unitary objects, not simple sums of the parts into which analysis would resolve them. And they are what they are in relation to organisms whose environment they constitute. When we reduce a thing to parts we have destroyed the thing that was there. It is no longer a table or a tree or an animal. And even if by some process these parts should coalesce and become the things that they were, it still remains the case that they would not be things they were in this environment of this organism, if they ceased to be parts of this environment. We refer to these differences as the meanings these things have in their relationship to the organisms. Still, these meanings belong to the things, and are as objective as are those characters of the things that belong to them in the environments of other organisms. The sensuous characters are largely the same for organisms endowed with like apparatus of sense perception; though there are always differences in these characters due to differences in these apparatuses and to the conditions under which the things enter into relation with the senses of the various organisms. Other characters such as nutritiousness for an animal that can digest and assimilate certain things, dangerousness or protection, equally arise as objective characters when the objects enter relations with certain organisms, and take on these meanings. Such characters evidently emerge with the development of organisms and in their changing experience.
Science undertakes to isolate the conditions under which these new things arise, or have arisen. It abstracts from the peculiarities of particular experience and seeks that which is common among as many experiences as possible. It thus reaches things which upon the supposition of analysis have a common reality apart from the particular experience within which the analysed objects existed. We thus reach
(118) things that belong, to any possible experience up to the limits of our powers of generalization. The question arises whether that which answers to these widest generalizations escapes from experience, and from the characters and meanings which belong to experience. Can we in thought reach that which is independent of the situation within which the thinking takes place? I am asking the question not from the standpoint of the metaphysician and logician, who start with an apparatus of thinking and a cognition that are preconditions of the experience within which they appear; but from the standpoint of a science that has undertaken to trace the development of thought out of the lowliest types of behavior. If we posit a mind having an inherent power of entering into cognitive relation with objects that are simply there for its awareness and thought, this mind may be able to identify things independent of the experiences of the organisms that have become in some fashion endowed with such minds. Or we may with the idealists transfer all environments to mind itself. But if mind is simply an emergent character of certain organisms in their so-called intelligent responses to their environments, mind can never transcend the environment within which it operates. Nor can it by generalizing all possible experiences get beyond any possible experience; for it must do its thinking within some experience, and the meanings that arise out of the relation of the minded organism to its environment must belong to the object of its perception and its widest thought. It may be claimed that an emergent evolution can not deny the possibility of the emergence of a realist's mind, with just that power of entering into cognitive relations with objects; the answer, however, will be found in the natural history of mind and the study of mental operations.
