The theory of natural selection is a rich systematization of biological knowledge without a first principle. When formulations of a proposed principle of natural selection are examined carefully, each is seen to be exhaustively analyzable into a proposition about sources of fitness and a proposition about consequences of fitness. But whenever the fitness of an organic variety is well denned in a given biological situation, its sources are local contingencies together with the background of laws from disciplines other than the theory of natural selection; and the consequences of fitness for the long range fate of organic varieties are essentially applications of probability theory. Hence there is no role and no need for a principle of the theory of natural selection, and any generalities that may hold in that theory are derivative rather than fundamental.

THESIS

The main thesis of this paper is that the biological theory of natural selection does not contain a general principle of natural selection and has no need for such a principle.

This thesis in no way denies that natural selection is one of the primary mechanisms shaping the constitution of the biosphere; and in no way is it an endorsement of any of the well-known alternatives to or modifications of the theory of natural selection, such as creationism, Lamarckianism, or orthogenesis. Nor does my thesis entail that no general principles are to be found in the theory of evolution as a whole, of which the theory of natural selection is a part.

In quantum theory as it is currently formulated the measurement of an observable quantity of a physical system is the occasion for a change of state of the system, except when the state prior to the measurement is an eigenstate of the observable. Two proposals for interpreting this kind of change are examined in detail, and several variant proposals are considered briefly. According to the interpretation proposed by von Neumann, and by London and Bauer the change of state is completed only when the result of the observation is registered in the observer's consciousness. Although this interpretation appears to be free from inconsistencies, it is not supported by psychological evidence and it is difficult to reconcile with the inter subjective agreement of several independent observers. According to the interpretation proposed by Bohr, the change of state is a consequence of the fundamental assumption that the description of any physical phenomenon requires reference to the experimental arrangement. Bohr's proposals are valuable as practical maxims in scientific theory, but they are shown to involve the renunciation of any ontological framework in which all types of events – physical and mental, microscopic and macroscopic – can be located. It is concluded that a satisfactory account of the observation of microphysical quantities is unlikely if the present formulation of quantum theory is rigorously maintained.

INTRODUCTION

There are two distinct problems concerning the relationship between physical objects and consciousness.

ASPECTS OF THE PROBLEM

One of the most pervasive features of the natural world is the existence of reasonably stable systems composed of well-defined parts which are to a large extent unchanged by entering into composition or leaving it. The problem of parts and wholes is to understand with the greatest possible generality the relation between the components and the composite system.

The parts–wholes problem has an ontological aspect, which concerns the properties of the components and the composite system without explicit consideration of how knowledge of them is obtained. Among the ontological questions are the following: Is there an ultimate set of entities which cannot be subdivided and which are therefore “atomic” in the etymological sense? If the properties of the components are fully specified, together with the laws governing their interactions, are the properties of the composite system then fully determined? In particular, are those properties of composite systems which are radically different from those of the components, and which might properly be characterized as “emergent,” also definable in terms of the latter? Do composite systems belong, always or for the most part, to “natural kinds”? Is the existence of natural kinds explicable in terms of the laws governing the components? Are both the possible taxonomy and the actual taxonomy of natural kinds thus explicable? Is there a hierarchy of “levels of description” – i.e., microscopic, macroscopic, and possibly intermediate – such that laws can be formulated concerning a coarser level without explicit reference to the properties at a finer level of description?

The Principle of Maximum Entropy (hereafter referred to as “PME”) was proposed by E. T. Jaynes [1957, 1963, 1967, 1968, 1976, 1979] as a fundamental instrument of inductive inference. Jaynes's ideas have been enthusiastically accepted and applied by numerous scientists, engineers, and philosophers, but there have also been critics and skeptics. Because of several papers over the past decade [Friedman and Shimony 1971; Friedman 1973; Shimony 1973; Dias and Shimony 1981] my collaborators and I are considered to belong to the second group. Our effort, however, has not been entirely negative. We have attempted to discover tacit presuppositions of PME and thereby to determine the circumstances under which it may legitimately be applied. The present paper is a summary of our results, with only a sketch of some of the mathematical arguments.

We share with Jaynes the conviction that an epistemic concept of probability plays a central role in inductive inference. If h is a hypothesis and d is an evidential proposition (not self-contradictory), then we suppose that it is meaningful to speak of “the probability of h upon assumption that d is the total body of evidence” and to consider this probability to be a definite real number denoted by “P(h | d)”. The statement “P(h | d) = r” is to be interpreted as “the reasonable degree of belief in h, if d is the total evidence, is r”.

INTRODUCTION

The first purpose of this paper is to raise questions about the epistemological status of some of the principles of protophysics, particularly of the protophysics of time (Section 2). Reasons will be given for doubting that their status can be adequately clarified unless there is a retrenchment of the protophysical program. The second purpose is to suggest a revision of the protophysical program (Sections 3 and 4): instead of making the methodology of space and time measurements strictly prior to physics, this methodology should be developed in tandem with physics. A discussion of Newton's treatment of absolute time will give the proposed revision some historical and conceptual specificity. The third purpose is to indicate briefly the implications of the proposed revision for relativistic kinematics and for epistemology in general (Section 5).

THE EPISTEMOLOGICAL STATUS OF PROTOPHYSICAL PRINCIPLES

Some quotations from P. Janich's Protophysics of Time will be useful starting points for analysis.

Recently there have been several extremely interesting expositions of a thesis which is implicit in the evolutionary view of man, but which had (at least after the early waves of enthusiasm for Darwinian ideas) been rather neglected: that human perceptual powers are as much a result of natural selection as any feature of organisms, with selection generally favoring improved recognition of objective features of the environment in which our pre-human ancestors lived. That these studies of perception from an evolutionary point of view have not influenced most writers on epistemology is one of many symptoms of the continuing dissociation of philosophy from the natural sciences. To be sure, at least one reason for abstaining from evolutionary considerations in epistemological inquiry is obvious and weighty: namely, to avoid begging questions, since the evolutionary view of human perceptual powers seems to be antecedently committed to the propositions of a specific epistemological position, the causal theory of perception. This reason will appear decisive, however, only if the mission of epistemology is conceived to be the establishment of an irrefutable foundation upon which the entire edifice of knowledge is to be erected. If, instead, epistemology is conceived to have a dialectical structure, in which the starting point of an investigation is subject to subsequent correction and refinement, then one can legitimately ask whether evolutionary considerations, despite their presuppositions, can strengthen the case for the causal theory.

If a spin-½ particle is placed in a constant uniform magnetic field for a time t during which, classically, the Larmor precession angle would be θ, then according to quantum mechanics the components of the spin part of the wave function undergo phase changes of ±θ/2. Hence, corresponding to a classical precession of 2π radians, there is a sign change of the spinor, whatever the initial polarization may be. Bernstein pointed out that this sign change can be observed by coherently splitting a fermion beam, subjecting one part to the magnetic field, and coherently recombining the parts. Evidently, the same interference effect can be achieved by subjecting the two parts of the beam to fields which would classically cause precessions of π radians in opposite senses. He noted advantages in studying neutral rather than charged particles, and outlined a proposal for an interferometry experiment with neutrons.

The recent invention and application of a remarkable single-crystal neutron interferometer greatly increases the feasibility of observing the sign change. In the experiment of Ref. 3 a neutron beam is split, and the two parts follow paths of different elevations. The interference of the recombined parts exhibits the effect of gravitational potential difference between the two elevations. In the experiment which we propose, the paths could be kept at the same elevation, but phase differences would be produced by appropriate magnetic fields.

A scientist is supposed to have a complete and thorough knowledge, at first hand, of some subjects and, therefore, is usually expected not to write on any topic of which he is not a master. This is regarded as a matter of noblesse oblige. For the present purpose I beg to renounce the noblesse, if any, and to be freed of the ensuing obligation. My excuse is as follows:

We have inherited from our forefathers the keen longing for unified, all-embracing knowledge. The very name given to the highest institutions of learning reminds us, that from antiquity and throughout many centuries the universal aspect has been the only one to be given full credit. But the spread, both in width and depth, of the multifarious branches of knowledge during the last hundred odd years has confronted us with a queer dilemma. We feel clearly that we are only now beginning to acquire reliable material for welding together the sum total of all that is known into a whole; but, on the other hand, it has become next to impossible for a single mind fully to command more than a small specialized portion of it.

I can see no other escape from this dilemma (lest our true aim be lost for ever) than that some of us should venture to embark on a synthesis of facts and theories, albeit with second-hand and incomplete knowledge of some of them -and at the risk of making fools of ourselves.

The first half of the nineteenth century was marked by the discovery of a variety of new phenomena in electricity and magnetism, and the general task to which Maxwell then addressed himself, beginning in the 1850s, was the development of a unified electromagnetic theory that would incorporate all of these phenomena. Section 1 of this chapter explores the broad background in nineteenth-century electromagnetic experiment and theory for Maxwell's work. Section 2 deals with the particular scientific and mathematical education and training that Maxwell brought to his work in electromagnetic theory, including his educational experiences at the universities of Edinburgh and Cambridge, as well as the epistolary tutelage of William Thomson. Finally, Section 3 deals with the methodological approach – growing out of the combined Scottish and Cambridge backgrounds – that Maxwell brought to his work.

Electricity and magnetism from Oersted to the 1840s

The discovery of the magnetic effects of electric currents, announced by Hans Christian Oersted in July 1820, defined the agenda for the study of electricity and magnetism during the following decades. Viewed in broad terms, Oersted's discovery had implications in two directions: First, Oersted's research had been undertaken in the context of widespread preoccupation – following Alessandro Volta's invention of the voltaic pile in 1800 – with the connections between electric currents and other physical phenomena, including chemical effects, heat, and light.

As he pursued the task of constructing a unified account of electromagnetic phenomena from a field-theoretic point of view – from his initial explorations under Thomson's tutelage in 1854 through his work on a second edition of the Treatise on Electricity and Magnetism in the months before his death in 1879 – Maxwell was unwavering in his basic commitment to a broad mechanical framework, within the confines of which this task was to be carried out. Within this broad mechanical framework, however, there were various methodological options at Maxwell's disposal – traceable to his experiences at both Edinburgh and Cambridge, and also to his interaction with William Thomson – and Maxwell was to make full use of this variety of options, in response to the shifting needs of his evolving research program. In brief, Maxwell started out using an analogical approach to mechanical representation, rooted in Scottish skepticism and reflecting a desire to proceed with minimal physical commitment at the outset; in this context, he presented the mechanical images in his first major paper on electromagnetic theory, “On Faraday's Lines of Force” (1855–6), as purely illustrative, with no claim whatever to realistic status. Subsequently, responding to William Thomson's judgment that the time had come to go beyond mere analogy in electromagnetic theory and to begin the task of constructing a realistic mechanical theory, Maxwell developed his molecular-vortex representation of the electromagnetic field in the paper entitled “On Physical Lines of Force” (1861–2).

A BIOLOGICAL BLIND ALLEY?

We may, I believe, regard it as extremely improbable that our understanding of the world represents any definite or final stage, a maximum or optimum in any respect. By this I do not mean merely that the continuation of our research in the various sciences, our philosophical studies and religious endeavour are likely to enhance and improve our present outlook. What we are likely to gain in this way in the next, say, two and a half millennia — estimating from what we have gained since Protagoras, Democritus and Antisthenes — is insignificant compared with what I am here alluding to. There is no reason whatever for believing that our brain is the supreme ne plus ultra of an organ of thought in which the world is reflected. It is more likely than not that a species could acquire a similar contraption whose corresponding imagery compares with ours as ours with that of the dog, or his in turn with that of a snail.

If this be so, then — though it is not relevant in principle — it interests us, as it were for personal reasons, whether anything of the sort could be reached on our globe by our own offspring or the offspring of some of us. The globe is all right. It is a fine young leasehold, still to run under acceptable conditions of living for about the time it took us (say 1,000 million years) to develop from the earliest beginnings into what we are now.

The historian of science cannot be unmindful of the fact that, for better or for worse, science, as practiced now and in the past, furnishes one of our central models of rational thought and judgment. Some would use history to demonstrate the worthiness of science as a model for rationality; others would use history to demonstrate the limitations of science in this respect. Above all, however, awareness of the paradigmatic role of science urges the historian of science to seriousness of purpose in trying to delineate and understand the practice of science in the past. In particular, I here endeavor to delineate and understand, in historical context, James Clerk Maxwell's seminal work in electromagnetic theory. Understanding of matters of any significance, however, seems never to come easily: This book has been long in gestation, and it makes some demands of its reader.

I was introduced to the historical study of Maxwell by Martin Klein, whose work and counsel have been seminal for me.

Jed Buchwald, Francis Everitt, Peter Harman, John Heilbron, Ole Knudsen, and David Wilson have furnished ideas, sources, and encouragement beyond what scholarly citations can acknowledge.

My work has been enriched by the conversation as well as the scholarly publications of Joan Bromberg, Geoffrey Cantor, Alan Chalmers, Michael Crowe, Gregory Good, John Hendry, Jonathan Hodge, Robert Kargon, Donald Moyer, Richard Olson, Paul Theerman, and Norton Wise.