Methodology in Aristotle’s Theory of Spontaneous Generation

Aristotle’s theory of spontaneous generation offers many puzzles to those who wish to understand his theory both within the context of his biology and within the context of his more general philosophy of nature. In this paper, I approach the difficult and vague elements of Aristotle’s account of spontaneous generation not as weaknesses, but as opportunities for an interesting glimpse into the thought of an early scientist struggling to reconcile evidence and theory. The paper has two goals: (1) to give as charitable and full an account as possible of what Aristotle’s theory of spontaneous generation was, and to examine some of its consequences; and (2) to reflect on Aristotle as a scientist, and what his comments reveal about how he approached a difficult problem. In particular, I propose that the well-recognized problem of the incompatibility between Aristotle’s concept of spontaneity and his theory of spontaneous generation presents an opportunity for insight into his scientific methodology when approaching ill-understood phenomena.     

Questions of Methodology in Aristotle’s Zoology: A Medieval Perspective

During the Middle Ages Aristotle’s treatises were accessible to intellectuals via translations and commentaries. Among his works on natural philosophy, the zoological books received relatively little scholarly attention, though several medieval commentators carefully studied Aristotle’s investigations of the animal kingdom. Averroes completed in 1169 a commentary on an Arabic translation of Aristotle’s Parts of Animals and Generation of Animals. In 1323 Gersonides completed his supercommentary on a Hebrew translation of Averroes’ commentary. This article examines how these two medieval commentators interpret the first book of Aristotle’s Parts of Animals, at the center of which stand methodological questions regarding the study of animals. Aristotle’s discussion of classification is presented by Averroes and Gersonides in light of an epistemological debate concerning the requisite method for scientific inquiries and discoveries. Sense perception is contrasted with rational reasoning, and ultimately a combined method is proposed, sense perception maintaining supremacy. These commentators outline a clear link between the systematic arrangement of animal species as offered by Aristotle, and his subsequent logical demonstrations which, according to them, form the core of biological investigations.     

Origins of Life: Chemical and Philosophical Approaches

In this article we address selected important milestones of chemical evolution that led to life. The first such milestone could be achieved by Oparin’s model, which accounts for the early stages of chemical evolution. These occurred at the dawn of development of primitive chemical systems that were pre-RNA. Oparin’s model consists of spontaneous formation of coacervates that encapsulate chemical matter, undergo primitive self-replication, and provide a pathway to a primitive metabolism. We review the experimental updates of his model from our laboratory and discuss types of selection that could have occurred in these primitive systems. Another major milestone in chemical evolution is the transition from abiotic to biotic. This has occurred later, after the RNA world evolved. A controversy of what life is interferes with the efforts to elucidate this transition. Thus, we present various definitions of life, some of which specifically include the requirements and mechanisms for this transition. Self-replication is one of the major requirements for life. In this context we re-examine the question if viruses, which do not have capability to self-replicate, are alive. We draw on philosophy of Hegel, Aristotle, Rescher, Priest, and Fry to guide us in our endeavors. Specifically, we apply Hegel’s law on quantity-to-quality transition to abiotic-to-biotic transition, Aristotle’s philosophy to the definition of life, Priest’s dialetheism to the question if viruses are alive or not, Fry’s philosophy to the beginning of natural selection in chemical evolution, and Rescher’s philosophy to the possible cognitive bias toward simple definitions of life.     

Aristotle's study of the animal world: the case of the kobios and phucis

Aristotle was a remarkable observer of the living world. He made detailed observations on the anatomy and life history characteristics of many organisms as part of a larger study into the differentiae (diaphora) of groups of animals. This reexamination of Aristotle's observations of two small fishes is a study into the work or the way of being of particular organic wholes. As such, it is directed by three main objectives: to evaluate the accuracy of those observations Aristotle makes with regard to the kobios and phucis in the History of Animals, as well as to understand how he might have conducted his research; to determine whether aspects of those observations would ground more philosophical arguments; and to contribute to the understanding of the basic biology of these fishes. In so doing, this article also may introduce a new generation of biologists to the richness of Aristotle's biological observations and the questions that motivated them.     

On Darwin's 'metaphysical notebooks'. II: "Metaphysics" and final cause.

The first part of this paper was published in Rivista di Biologia/Biology Forum 94 (2001). In the second part below an examination is made of the meaning of the term Metaphysics in some passages of the Darwinian Notebooks for the years 1836-1844. Metaphysics no longer defines a field of philosophical enquiries mainly concerning the being and the essence after the manner of Aristotle; it now refers to a kind of philosophy of mind after the manner of J. Locke's criticism of the Hypokeimenon. However Aristotle's Metaphysics also encompasses a treatment of the idea of causes, and of final cause particularly, in the explanation of events, and in the explanation of natural phenomena especially. The criticism of the idea of final cause in the interpretation of the world of life is one of Darwin's foundational acts in his early years. When conceiving his Système du monde, in the last years of the XVIII Century, Laplace could think that God is a hypothesis not really needed by science, as we are told. For the knowledge of organic nature to attain the status of science, it remained to be shown that since--certain of the exemplariness of Newton's Principles as much as cautious before the mystery of life--did not need the hypothesis of final ends in order to understand and explain the productions of the living nature: not only in the form of that final cause (the First Cause, the Vera Causa) in which Natural Theology still rested, but also in the form of nature's inner finality which still moulded Whewell's Kantian philosophy. Such demonstration is a very important subject in Darwin's early enquiries, where he criticises finalism as a projection of self-conceiving Man, likely inherited from a knowing of causality in nuce to be found also in animals.     

The discovery of the body: human dissection and its cultural contexts in ancient Greece.

In the first half of the third century B.C, two Greeks, Herophilus of Chalcedon and his younger contemporary Erasistratus of Ceos, became the first and last ancient scientists to perform systematic dissections of human cadavers. In all probability, they also conducted vivisections of condemned criminals. Their anatomical and physiological discoveries were extraordinary. The uniqueness of these events presents an intriguing historical puzzle. Animals had been dissected by Aristotle in the preceding century (and partly dissected by other Greeks in earlier centuries), and, later, Galen (second century A.D.) and others again systematically dissected numerous animals. But no ancient scientists ever seem to have resumed systematic human dissection. This paper explores, first, the cultural factors--including traditional Greek attitudes to the corpse and to the skin, also as manifested in Greek sacred laws--that may have prevented systematic human dissection during almost all of Greek antiquity, from the Pre-Socratic philosopher-scientists of the sixth and fifth centuries B.C. to distinguished Greek physicians of the later Roman Empire. Second, the exceptional constellation of cultural, political, and social circumstances in early Alexandria that might have emboldened Herophilus to overcome the pressures of cultural traditions and to initiate systematic human dissection, is analyzed. Finally, the paper explores possible reasons for the mysteriously abrupt disappearance of systematic human dissection from Greek science after the death of Erasistratus and Herophilus.     

The Philosophical Origins of Mitchell's Chemiosmotic Concepts

Mitchell's formulation of the chemiosmotic theory of oxidative phosphorylation in 1961 lacked any experimental support for its three central postulates. The path by which Mitchell reached this theory is explored. A major factor was the role of Mitchell's philosophical system conceived in his student days at Cambridge. This system appears to have become a tacit influence on his work in the sense that Polanyi understood all knowledge to be generated by an interaction between tacit and explicit knowing. Early in his life Mitchell had evolved a simple philosophy based on fluctoids, fluctids and statids which was developed in a thesis submitted for the z at the University of Cambridge, England. This aspect of his work was rejected by the examiners and became a tacit element in his intellectual development. It is argued from his various publications that this philosophy can be traced as an underlying theme behind much of Mitchell's theoretical writing in the 50's leading, through his notion of vectorial metabolism, to the formulation and amplification of the chemiosmotic theory in the sixties. This philosophy formed the basis for Mitchell of his understanding of biological systems and gave him his unique approach to cell biology. This revised version was published online in July 2006 with corrections to the Cover Date.     

Aristotle on the Mechanism of Inheritance

In this paper I address an important question in Aristotle’s biology, What are the causal mechanisms behind the transmission of biological form? Aristotle’s answer to this question, I argue, is found in Generation of Animals Book 4 in connection with his investigation into the phenomenon of inheritance. There we are told that an organism’s reproductive material contains a set of “movements'' which are derived from the various “potentials'' of its nature (the internal principle of change that initiates and controls development). These “movements,'' I suggest, function as specialized vehicles for communicating the parts of the parent’s heritable form during the act of reproduction. After exploring the details of this mechanism, I then take up Aristotle’s theory of inheritance proper. At the heart of the theory are three general principles (or ‘laws’) that govern the interactions between the maternal and paternal movements, the outcome of which determines the pattern of inheritance for the offspring. Although this paper is primarily aimed at providing a detailed analysis of Aristotle’s account of inheritance, the results of that analysis have implications for other areas of Aristotle’s biology. One of the most interesting of these is the question of whether Aristotle’s biology is anti-evolutionary (as traditionally assumed) or whether (as I argue) it leaves room for a theory of evolution by natural selection, even if Aristotle himself never took that step.     

The interface of natural theology and science in the ethology of W. H. Thorpe

Conclusion It should be clear by now the extent to which many features of Thorpe's interpretation of animal behavior and of the animal mind rested, at bottom, not simply on conventional scientific proofs but on interpretive inferences, which in turn rested on a willingress to make extensions of human experience to animals. This, in turn, rested on his view of evolution and his view of reality. And these were governed by his natural theology, which was the fundamental stratum of his intellectual experience.Contrary to the scientific ethos, which restricts theory choice to scientific issues alone, Thorpe's career suggests that the actual reasons for theory choice among scientists often are not limited to science, but are multiple and may sometimes be difficult to discover. It is largely because Thorpe took a public part in the natural theology enterprise that we can know something about his religious beliefs and so can see their probable influence on his scientific decisions. Similar beliefs of other scientists are sometimes harder to get at. Most may be practically beyond discovery, for the ethos of science has discouraged public professions of personal belief in relation to scientific work.¹⁰¹ Yet does it seem plausible that, for example, the restriction of self-consciousness to humans by some scientists is a purely scientific decision?¹⁰² Surely not, any more than that the strong influence of natural theology on Thorpe's thought means that he was not a good scientist. His natural theology may have led him into incautious enthusiasms regarding the animal mind — such as the potential if unrealizable linguistic ability of chimpanzees — through a bias in favor of the continuity of emergents in a progressive evolutionary system, just as it led him to advocate animal consciousness long before the recent upsurge of interest, but the scientific integrity of his work overall is unimpeachable. And yet, that work is not comprehensible historically as science alone. Personal philosophy must not be discounted in writing the history of recent science. This somewhat obvious conclusion (obvious to historians of science) needs emphasis, for we are still prone to think that the sciences of our own time provide their own internal dynamic that is in itself sufficient to account for their content and development.     

Darwin on Aristotle

Charles Darwin's famous 1882 letter, in response to a gift by his friend, William Ogle of Ogle's recent translation of Aristotle's Parts of Animals, in which Darwin remarks that his “two gods,” Linnaeus and Cuvier, were “mere school-boys to old Aristotle,” has been thought to be only an extravagantly worded gesture of politeness. However, a close examination of this and other Darwin letters, and of references to Aristotle in Darwin's earlier work, shows that the famous letter was written several weeks after a first, polite letter of thanks, and was carefully formulated and literally meant. Indeed, it reflected an authentic, and substantial, increase in Darwin's already high respect for Aristotle, as a result of a careful reading both of Ogle's Introduction and of more or less the portion of Ogle's translation which Darwin says he has read. Aristotle's promotion to the pantheon, as an examination of the basis for Darwin's admiration of Linnaeus and Cuvier suggests, was most likely the result specifically of Darwin's late discovery that the man he already knew as “one of the greatest ... observers that ever lived” (1879) was also the ancient equivalent both of the great modern systematist and of the great modern advocate of comparative functional explanation. It may also have reflected some real insight on Darwin's part into the teleological aspect of Aristotle's thought, indeed more insight than Ogle himself had achieved, as a portion of their correspondence reveals. This revised version was published online in July 2006 with corrections to the Cover Date.     

Causality and complexity: the myth of objectivity in science

Two distinctly different worldviews dominate today's thinking in science and in the world of ideas outside of science. Using the approach advocated by Robert M. Hutchins, it is possible to see a pattern of interaction between ideas in science and in other spheres such as philosophy, religion, and politics. Instead of compartmentalizing these intellectual activities, it is worthwhile to look for common threads of mutual influence. Robert Rosen has created an approach to scientific epistemology that might seem radical to some. However, it has characteristics that resemble ideas in other fields, in particular in the writings of George Lakoff, Leo Strauss, and George Soros. Historically, the atmosphere at the University of Chicago during Hutchins' presidency gave rise to Rashevsky's relational biology, which Rosen carried forward. Strauss was writing his political philosophy there at the same time. One idea is paramount in all this, and it is Lakoff who gives us the most insight into how the worldviews differ using this idea. The central difference has to do with causality, the fundamental concept that we use to build a worldview. Causal entailment has two distinct forms in Lakoff 's analysis: direct causality and complex causality. Rosen's writings on complexity create a picture of complex causality that is extremely useful in its detail, grounding in the ideas of Aristotle. Strauss asks for a return to the ancients to put philosophy back on track. Lakoff sees the weaknesses in Western philosophy in a similar way, and Rosen provides tools for dealing with the problem. This introduction to the relationships between the thinking of these authors is meant to stimulate further discourse on the role of complex causal entailment in all areas of thought, and how it brings them together in a holistic worldview. The worldview built on complex causality is clearly distinct from that built around simple, direct causality. One important difference is that the impoverished causal entailment that accompanies the machine metaphor in science is unable to give us a clear way to distinguish living organisms from machines. Complex causality finds a dichotomy between organisms, which are closed to efficient cause, and machines, which require entailment from outside. An argument can be made that confusing living organisms with machines, as is done in the worldview using direct cause, makes religion a necessity to supply the missing causal entailment.     

The galenic and hippocratic challenges to Aristotle's conception theory

Conclusion As a result of this case study, additional questions arise. These can be cast into at least three groups. The first concerns the development of critical empiricism in the ancient world: a topic of much interest in our own century, expecially with regard to the work of the logical empiricists. Many of the same arguments are present in the ancient world and were hotly debated from the Hippocratic writers through and beyond Galen. Some of the ways in which Galen reacts to Hippocratic and Aristotelian influences may, in part, be explained by Galen's own posture as a so-called Dogmatist. Both the Empirics and the Methodists offered alternative viewpoints on the place, role, and limits of observation in biomedical research. Though I have written on this relationship in the Hippocratic writers and Aristotle,⁴⁴ it remains to be discussed in detailed fashion just how critical empiricism acted in Galen's evaluation of biomedical problems (aporiai). Contrasts between Galen and his predecessors might further clarify this issue both as a historical question and as it affects the construction of biological theory.The second area explores the question of how one develops comprehensive theories. In this respect Galen follows Aristotle's methodology rather closely. Both look at what theories are available to them and then systematically review the problems raised, at the same time refuting what they find inadequate. This is an effective strategy, for it permits utilizing the best features of earlier work to fashion a new whole. Indeed, Galen himself seems to attribute his use of such a methodology to his ecletic medical and philosophical training. Both Aristotle and Galen endeavor to employ techniques of theory integration. That is, they use aspects of theories they have already espoused to deal with new problems. This suggests the emergence of formal, logical coherence as an element in theory evaluation. The obvious drawback is that it can cause mistakes in one area to be repeated and ingrained in other areas. Such errors, because they are at the very core of an explanatory framework, may take centuries to correct. Future studies may shed light on how theory integration acts both in a positive and in a negative way.Finally, this case study offers a glimpse of how science progresses. Even though the advances in medical technology were comparatively minor, there is a great deal more sophistication in the conception theoreis of Aristotle and Galen than was present in the Hippocratic writers. Some of this (in Galen's case) had to do with increased anatomic and physiological knowledge, but most, I believe, is due to the evolution of scientific knowledge. If further work were done specifically on this question, it might document more completely how scientific knowledge on a specific topic evolves. The mode of advancement is primarily through gradual refinement of the types of questions being asked by these ancient authors, and the ramifications of their answers.Ancient theories of conception offer a fine case study in the history and philosophy of how a theory begins the develops. I have tried to suggest some interrelationships among the more important theories, as they focused upon Aristotle's own conception theory. There has been renewed interest in such cases in recent years. It is my hope that future specialized studies will increase our knowledge of method and practice in these important case studies and thereby augment our understanding of the genesis and application of biological theories.     

Hegel's notion of natural purpose

This paper argues that the notion of natural purpose developed by Hegel can only be thoroughly grasped by considering its intimate connection with the idea of contradiction and, particularly, with what Hegel in his philosophy of nature called the 'activity of deficiency'. This expression is used by Hegel to denote the ontological situation of every living being, which is embodied most authentically in the concepts of need and drive. For Hegel, life itself is imbued with contradiction because it is inextricably bound up with what it lacks: its identity is at one with its negation. This paper defends the thesis that Hegel's philosophy-and not just his philosophy of nature-can be characterized as an 'ontology of life' (to use the same expression that Martin Heidegger applied to Aristotle's De Anima), or more precisely, as an ontology of living individuality.     

Harvey,Aristotle and the Weather Cycle

It is well known that Harvey was influenced by Aristotle. This paper seeks to show that Harvey's quantitative argument for the circulation and his analogy of the heart with a pump do not go beyond Aristotle and may even have been inspired by passages in Aristotle. It also considers the fact that Harvey gives much greater prominence to a macrocosm/microcosm analogy between the weather cycle and the circulation of the blood than he does to the pump analogy. This analogy is prominent in both the preface to the king and pivotal chapter eight of De Motu Cordis, and may indicate a significant influence from the Renaissance natural magic tradition. The full implications of this analogy are critical for Harvey's conception of the nature of the circulation, especially the constant interconversion of venous and arterial blood and the passage of blood through the lungs. The tendency to assume that Harvey had a superior method since he made such an important discovery may have led not only to overestimation of the influence from the new science of the seventeenth century, but also to underestimation of influence from the magical tradition.     

Les thérapies comportementales et cognitives, l’épicurisme et le stoïcisme

This article aims to show that philosophy, particularly Epicureanism and Stoicism, had an essentially therapeutic role in antiquity — the various schools of philosophy dispensing specific teachings aimed at treating mental suffering, in a precise place (the scholé), with a master and a specified methodology. Of course, it may seem anachronistic to try and compare a modern, progressive and proven therapeutic method such as cognitive behavioural therapy (CBT, TCC in French) with a frequently dogmatic, 2000-year-old school of philosophy. And yet, the difference is not as clear-cut as we might think, since the two have much in common, such as similar kinds of suffering, a referent (or therapist), common methods (language, reasoning) and a common goal (peace of mind). We therefore intend to try and synthesise the meeting points and also the differences between two main schools of antique philosophy and CBT.     

The future of philosophy

There is no sharp dividing line between science and philosophy, but philosophical problems tend to have three special features. First, they tend to concern large frameworks rather than specific questions within the framework. Second, they are questions for which there is no generally accepted method of solution. And third they tend to involve conceptual issues. For these reasons a philosophical problem such as the nature of life can become a scientific problem if it is put into a shape where it admits of scientific resolution. Philosophy in the 20th century was characterized by a concern with logic and language, which is markedly different from the concerns of earlier centuries of philosophy. However, it shared with the European philosophical tradition since the 17th century an excessive concern with issues in the theory of knowledge and with scepticism. As the century ends, we can see that scepticism no longer occupies centre stage, and this enables us to have a more constructive approach to philosophical problems than was possible for earlier generations. This situation is somewhat analogous to the shift from the sceptical concerns of Socrates and Plato to the constructive philosophical enterprise of Aristotle. With that in mind, we can discuss the prospects for the following six philosophical areas: (1) the traditional mind-body problem; (ii) the philosophy of mind and cognitive science; (iii) the philosophy of language; (iv) the philosophy of society; (v) ethics and practical reasons; (vi) the philosophy of science. The general theme of these investigations, I believe, is that the appraisal of the true significance of issues in the philosophy of knowledge enables us to have a more constructive account of various other philosophical problems than has typically been possible for the past three centuries.     

Ernst Mayr,naturalist: His contributions to systematics and evolution

Ernst Mayr's scientific career continues strongly 70 years after he published his first scientific paper in 1923. He is primarily a naturalist and ornithologist which has influenced his basic approach in science and later in philosophy and history of science. Mayr studied at the Natural History Museum in Berlin with Professor E. Stresemann, a leader in the most progressive school of avian systematics of the time. The contracts gained through Stresemann were central to Mayr's participation in a three year expedition to New Guinea and The Solomons, and the offer of a position in the Department of Ornithology, American Museum of Natural History, beginning in 1931. At the AMNH, Mayr was able to blend the best of the academic traditions of Europe with those of North America in developing a unified research program in biodiversity embracing systematics, biogeography and nomenclature. His tasks at the AMNH were to curate and study the huge collections amassed by the Whitney South Sea Expedition plus the just purchased Rothschild collection of birds. These studies provided Mayr with the empirical foundation essential for his 1942Systematics and the Origin of Species and his subsequent theoretical work in evolutionary biology as well as all his later work in the philosophy and history of science. Without a detailed understanding of Mayr's empirical systematic and biogeographic work, one cannot possibly comprehend fully his immense contributions to evolutionary biology and his later analyses in the philosophy and history of science.     

Husserl's Crisis as a crisis of psychology

This paper places Husserl's mature work, The Crisis of the European Sciences, in the context of his engagement with--and critique of--experimental psychology at the time. I begin by showing (a) that Husserl accorded psychology a crucial role in his philosophy, i.e., that of providing a scientific analysis of subjectivity, and (b) that he viewed contemporary psychology--due to its naturalism--as having failed to pursue this goal in the appropriate manner. I then provide an analysis of Husserl's views about naturalism and scientific philosophy. Some central themes of the Crisis are traced back to Husserl's earlier work and to his relationship with his teacher, Franz Brentano, with whom he disagreed about the status of "inner perception" as the proper scientific method for a phenomenological analysis. The paper then shows that Husserl was well aware of at least one publication about the crisis of psychology (Bühler's 1927 book), and it teases out some aspects of the complicated relationship between Husserl and members of the Würzburg School of thought psychology: The latter had drawn on Husserl's writings, but Husserl felt that they had misunderstood his central thesis. I conclude by placing Husserl's work in the wider context of scientific, cultural, and political crisis-discourses at the time.     

W. K. Brooks's role in the history of American biology

Conclusion The results of this study indicate that the reputation of W. K. Brooks was aided significantly by historical circumstances. The first of these factors was the unique historical role of Johns Hopkins University in American graduate education. The second was the impact of European experimentalism on American biologists and the consequent increase of experimentation in this country.Johns Hopkins, as an institution, greatly aided in the selection, nurture, and placement of Brooks's students. To these institutional forces, Brooks did add direction toward marine biology and facilities for marine research. Also, his teaching methods—which were reinforced by his own natural quietness and his poor health—did encourage self-reliance: Brooks simply could not dominate over the day-to-day activities of his students.The impact of European experimentalism was largely responsible for giving American biologists new approaches to problems which were beginning to assume major importance in biology. Several of Brooks's students, notably E. B. Wilson, T. H. Morgan, and Ross Harrison, were involved in this transfer of approaches and problems to America. In addition, a large number were influenced by working at the Marine Biological Laboratory at Woods Hole, where many of these new approaches were being used—in some cases for the first time, in this country. Both of these historical circumstances detract from Brooks's personal importance as an influential and directing force.That Brooks allowed his students to pursue their own research with comparative freedom is indisputable. Perhaps this is the criterion for an outstanding teacher. But the fact remains that none of his best students followed Brooks's own line of investigation or his own method of research. It is less important here to evaluate Brooks as a teacher than to understand his influence on the direction of biological thought in the twentieth century. This study suggests that his influence was less important in terms of setting a direction for research than has previously been believed. What it is apparent that Brooks accomplished was the setting forth of biological topics in a larger context through his insistence on the relevance of philosophy to scientific research. How much this directly influenced his students, especially those outstanding individuals who later made important advances, is difficult to determine. This paper has tried to show that, in terms of available evidence, Brooks does not seem to have had the profound influence on early twentieth-century biology that some historians have claimed.     

Professor Peter Jewell 1925–1998

Today it is sometimes forgotten how recently ecology and animal behaviour have emerged as respectable sciences from being merely glorified nature study. I can remember hearing, only half a century ago, a distinguished professor stating firmly at a meeting of the Society for Experimental Biology, I think it was, that 'In Cambridge we do not teach ecology!' The transition that has taken place in attitudes since those days owes much to people like Peter Jewell. With a background in agriculture and physiology, his decision in the early 1960s to take his skills out into the field, to attempt the elucidation of some of the many problems facing real animals in the real world, was an important shift of emphasis. He brought a grasp of physiological function, and concepts of experimental rigour learned in the laboratory, to subjects that had sometimes lacked these important values. The researches which followed, often carried out in collaboration with the many colleagues and students who were attracted by his philosophy and personality, were part of the growing stream of vigorous new ideas that have shaped present-day attitudes towards ecology and ecological research.