It probably is not too large an exaggeration to describe Bruce G. Trigger’s A History of Archaeological Thought as a monumental work. The breadth and depth of knowledge Trigger brings to bear in elucidating the development of archaeology as a serious academic discipline is often extraordinary. No less so is the equanimity with which he approaches most of the material, sensibly applauding landmark developments yet refraining from lambasting absurd trends (even when the latter might have been entirely appropriate). Lucidly written and rich in detail, A History of Archaeological Thought’s primary significance stems from Trigger’s scrupulous eye for context, not only in articulating the relationships among individual paradigms, but in situating said paradigms within the broader social contexts of their development. Such an approach not only renders salient the particular merits and weaknesses of various approaches, but charts the sometimes agonizing route archaeology has taken in becoming an ever more rigorous scientific discipline^*.

Ostensibly a history book, A History of Archaeological Thought is really about theory and how any given theory relates to the world it purports to describe – a point made clear in the opening chapter. If it were a novel, Trigger’s work would derive its primary narrative propulsion from the tension between positivist, realist, and idealist epistemologies. These ideas have ontological implications (as they must, if they are to function as coherent ways of knowing) but the primary fulcrum of interaction concerns how individuals might cultivate knowledge about the world, rather than what that world consists of. To that end, Trigger paints positivism and idealism as occupying opposite ends the epistemological spectrum, with realism striking something of a pragmatic middle ground (though it is certainly more closely aligned with positivism than idealism). This is a fair treatment: the most ardent positivists see science as an epistemology of the exclusively observable, while radical idealists would counter that sensory observations are so grossly manipulated by cognitive biases that objective – and therefore scientific – knowledge is illusory. Realism is much more closely aligned with positivism, but permits scientific endeavors some freedom to draw conclusions about the unobservable from the observable consequences thereof. In practice, many research programs fall within the interstices of these positions, and the investigators working within said programs do not always make their philosophical positions explicit. Nevertheless, they do serve to broadly encapsulate the competing (and occasionally cooperating) schools of thought that have shaped archaeology’s development as a scientific discipline.

In relatively short order, Trigger makes it clear that he believes social context is of considerable importance in understanding the way archaeology has changed over time. Although this position is now considered uncontroversial by all but the most naïve of empiricists, it was once considered anathema by staunch positivists. At the same time, the realization that scientific endeavors can be influenced by factors other than empirical results has lent an unwarranted veneer of credibility to extreme idealists championing the absolute subjectivity of knowledge. Rather than robbing science of its claims to progress, a thorough recognition of the social malleability of research reveals something far more subtle and interesting: that scientific progress, though certainly real, is far messier, more nebulous, and harder won than commonly believed.

Trigger begins his history proper by pointing out that curiosity about the past extends well into prehistory. That being the case, such interests were presumably fleeting, lacking as they did any official investment in sustained research. In Medieval Europe, transitory investigations of the past were limited by the at once fanciful and myopic scope of Biblical interpretation. During the European Renaissance, studies of the past took on a more formal structure. A nostalgic, idealized view of Greek and Roman cultures encouraged an interest in classical studies. Work in said field continued throughout the succeeding centuries, eventually leading to increasingly specialized and systematized research, despite a noteworthy trend toward theoretical conservatism. Regarding the progress of archaeology as a science, the most significant development during its disciplinary infancy (beyond a basic recognition of the value of empirical evidence) was almost certainly the rise of a community structure and the growing importance of peer-review.

The value of the aforementioned development is, of course, debatable. In keeping with Trigger’s externalist explanations, the context in which a science develops is often just as important as the internal changes that might alter it. Certainly without the increasing secularization of society that followed in the wake of the Protestant Revolution and the subsequent reinvigoration of rational and empirical inquiry of the Enlightenment, scientific progress – of any kind – would have been impossible. Nonetheless, the recognition that scientific progress was contingent upon a range of historical developments is not the same as recognizing what it takes for a given discipline to be scientific. Here, something of a digression into what exactly constitutes science is worthwhile.

As is often the case with any intellectual endeavor worth its salt, the delineation of what is science and what constitutes scientific progress has engendered considerable debate. Philosophers and scientists alike have levelled opinions, some more convincing than others. Karl Popper’s doctrine of falsificationism has proven massively influential, primarily due to its proposed solution to the problem of induction. Rendering scientific postulates falsifiable should open them up to the exacting razor of deductive logic. Unfortunately, scientific practice has proven far more unwieldy – and purportedly falsified theories far too resilient – for falsifiability to serve as a reasonable criteria for demarcating scientific practice or progress. Naturally, good scientific theories should be open to potential disconfirmation, at least providing a deductive trapdoor for fatally flawed concepts, but the general trend in science has been to cleave to a more broadly verificationist stance – in line with both positivist and realist schools of thought. That being the case, it is not sufficient to say an idea or paradigm counts as scientific if it has garnered a certain amount of corroborating evidence.

For one thing, individual scientists often lack the objectivity to fairly evaluate their theories in light of available evidence. Mutually incompatible theories can persist side by side, bolstered by considerable apparent evidence. Similarly, ideas that are known in retrospect to be inescapably (even ridiculously) wrong are, when in vogue, substantiated by impressive arrays of what seem to be empirical facts. Ptolemaic geocentricism, though convoluted, matched and explained a considerable range of observational evidence. In contesting it, Copernicus relied primarily on parsimony – a concept the natural world need not necessarily reflect. Along similar lines, the initial reaction against the naïve evolutionism espoused by some 19^th and early 20^th century fell out of favor largely as a consequence of ideological and sociological shifts, rather than a failure to accumulate substantiating evidence. Though Trigger never shows anything more than a correlation between the shifting social landscape and patterns of archaeological thought, A History of Archaeological Thought’s emphasis on social context is remarkably convincing when it comes to demonstrating the vicissitudes of scientific progress.

To this end, Trigger often adopts a Kuhnian perspective on what constitutes science and how scientific progress comes about. Often misconstrued as a drastically relativist take on science, Thomas Kuhn’s seminal work, The Structure of Scientific Revolutions (2012), called into question the absolute rationality of the process of scientific discovery. For Kuhn, a scientific enterprise could be distinguished by its community structure and its “puzzle-solving” orientation. Within scientific communities, scientific debates over the validity of competing theories are not resolved by exclusive reference to empirical findings, but through a process of persuasion that invokes certain value-laden criteria, such as parsimony or intelligibility. Kuhn did not disregard empirical results as a driving force in scientific change – indeed, he recognized a sustained lack of empirical corroboration as an important impetus driving scientific debates in the first place (1970) – but cast science and scientific progress as more or less emergent products of community structures. This, above all else, was Kuhn’s core insight: without a community structure, comprised of researchers with variably commensurable positions (as dictated by the exigencies of social context and individual history) science, or at least scientific progress, does not occur. This is precisely why the development of a professional community and systems of peer review are absolutely critical steps in the cultivation of any rigorous scientific discipline.

Bruce G. Trigger

This is a point Trigger’s work repeatedly substantiates as it articulates the dynamic patterns of critique and transformation that characterized work within the archaeological community. In the 19^th century, an optimistic – albeit crude and ethnocentric – faith in human progress gave rise to what appeared to be convincing pictures of cultural evolution. Critiques rooted in historical particularism, in concert with a growing pessimism concerning the ingenuity of humanity and an ideological rejection of European racism, eventually stripped early evolutionary explanations of their scientific credibility. Over time, the changes stemming from cross-disciplinary critiques became more nuanced, even as the techniques developed within individual disciplines became more sophisticated. The primary causal explanations forwarded by historical-particularists – diffusion and migration – were shown to be insufficient to account for a wide range of archaeological observations. Nevertheless, the application of historical-particularism as an overarching paradigm for structuring research and explanations persisted, facilitating the development of improved methods for establishing ever finer chronological controls over the archaeological record. It was only with the rise of neoevolutionism as pioneered by Leslie White and Julian Steward, and the subsequent prominence of processualism, that historical-particularism fell out of favor.

It was in the second half of the 20^th century that archaeology began to reach its full expression as a scientific discipline (that is, a discipline engaged in the ongoing process of using empirical evidence and a simultaneously cooperative and competive community structure to solve archaeological puzzles). That is not to say this is the point at which archaeology became a science, or that it was here that archaeology really started to explain things. Rather, it seems that by the middle of the 20^th century, archaeology had accumulated enough data, methodological sophistication, and theoretical diversity to become a mature, progressive scientific endeavor.

Kuhn was onto something when he stressed the importance of community structure, but his picture of what constituted science and scientific progress was only partial. First, he did not place enough emphasis on the role of empirical findings. Writing after the publication of The Structure of Scientific Revolutions, Imre Lakatos (1977) and Paul Thagard (1978) both highlighted the need for a successful scientific discipline to be capable of empirically resolving outstanding problems. Lakatos stressed the need for continuing verification and the discovery of novel facts, while Thagard suggested that scientific progress was to some degree relative – successful scientific programs could be distinguished by their ability to explain more phenomena than alternatives. Later, David Hull (2001; 1988) would further elaborate on the importance of competition (and cooperation) both within and among paradigms, developing an explicitly selectionist interpretation of scientific progress. A general – if ultimately incomplete – synthesis of the aforementioned works would suggest that a successful and progressive scientific discipline must, at the very least, include the following:

• A professional community, comprised largely of highly trained individuals (sufficient for discourse to be non-redundantly predicated on previous findings).
• A proliferation and diversification of perspectives within said discipline (facilitating conflict and cooperation).
• The critique of said perspectives with regard to criteria of coherence and corroborative evidence, in addition to a priori value criteria (simplicity, intelligibility, etc.)
• The subsequent refinement and further diversification of theoretical perspectives.
• The continued production of a professional community, theoretical diversity, empirical evaluation, and so forth…

As universities began to churn out more and more trained archaeologists, the discipline came to have a substantial population of competing (both subtly and overtly) ideas, both within and among paradigms. Marxists could debate the proper way to do Marxist archaeology, ethnoarchaeologists could debate the proper way to relate modern subsistence practices to archaeological evidence, and both Marxist archaeologists and ethnoarchaeologists could debate the propriety of each other’s core assumptions. Additionally, through the use of ever more refined analytical methods, 20^th century archaeology was beginning to acquire the empirical stores against which hypotheses could be judged, even as the proliferation and diversification of approaches under the processualist umbrella (ecological, behavioral, cognitive, general systems, etc.) encouraged the sort of cooperation and competition needed to drive scientific progress.

As Trigger illustrates, even postprocessualism – often retrospectively regarded as somewhat less than scientific – has contributed to the scientific progress of archaeological research. By making salient the difficulties inherent in archaeological interpretation and shedding light on the deeply ingrained political biases held by many researchers, postprocessual critiques have encouraged a level of self-awareness that has proven immensely valuable in the pursuit of scientific explanations for the patterns in the material record. Over time, the overemphasis of subjectivity encouraged by some postprocessual subdisciplines has undermined their own authority and validity as independent knowledge gaining activities, even as the convoluted use of reified constructs to investigate reified constructs has served to obfuscate – rather than clarify – anything relevant to archaeological method or interpretation. Nonetheless, the postprocessual school provides perhaps the most useful demonstration of the importance of theoretical diversity, mutual criticism, and competition. By stimulating thoughtful discussion concerning which types of questions are amenable to archaeological investigation and highlighting the types of socio-political baggage that tend to erode individual subjectivity, postprocessualism has helped cultivate a more rigorous scientific approach among those that continue to practice archaeology as science.

In the concluding chapters of A History of Archaeological Thought, Trigger makes note of the value inherent in theoretical diversity, praising the growth of multidiscipinary approaches and calling for more of the same. Darwinian archaeologists, for instance, might attempt to understand a given artifact sequence relative to potential selective pressures, drawing on the sophisticated methodological work of historical-particularists to create high-fidelity battleship curves in order to better understand the chronology of change, while simultaneously deploying the methods of zooarchaeologists and behavioral ecologists to tease out potential correlations between artifact change and subsistence practices. Such work can be further bolstered by employing an array of working hypothesis derived from a number of theoretical perspectives. Multidisciplinary approaches implicitly acknowledge the multicausal nature of human behavior, while multivocality decreases the chance that important patterns will be missed or illuminating questions ignored. The use of either – and preferably both – increases both the analytical tractability of archaeological questions and the confidence assigned to empirically justifiable answers.

Throughout the 20^th century – in particular with rise of processual archaeology – researchers have turned to the philosophy of science for guidance in building and refining their discipline. While this has been a fruitful pursuit, it has also been misleading. Inspired by the work of Carl Hempel, Lewis Binford cast the goals of archaeology as a search for the laws behind the regularities of human behavior. In essence, he was arguing that archaeology should model itself on physics. Such a desire was fundamentally misplaced. As Trigger points out (perhaps echoing Nicholas Maxwell) the logic of any science is given by the questions it seeks to ask. Human behavior and cultural systems are often extraordinarily complex and open to influence by a vast assortment of potential causes. The processes that govern human behavior and cultural change are shaped, to a considerable degree, by contingency. They are, in the language of complexity theorists, rather sensitive to initial conditions. Take the aforementioned problems and submerge them in the miasma of potenial ambiguity that is a dynamic depositional environment and remove all potential for manipulative experimentation and what results is a set of monumentally complex questions. Given this, Trigger argues that in some respects the goals of archaeological science probably dictate a different set of investigative parameters than those applicable in physics or chemistry[1]. Above all else, Trigger’s A History of Archaeological Thought – erudite and perspicacious as it is – makes one thing clear: the complexity of the questions is such that finding answers is only feasible through the application of a piecemeal, multidisciplinary approach. Furthermore, that recognition has been hard won. It should not be undervalued.

* A monothetic description of archaeology as scientific can be misleading. There are those within the discipline that practice archaeology as a science, but characterizing archaeology as a whole as a science is not entirely accurate. Some archaeologists produce research that fails to meet the criteria of science, while others outright disavow scientific veracity as a reasonable goal for archaeological research.

[1] I have to disagree with Trigger’s suggestion that parsimony might not be a good value criteria for assesing archaeological explanations. Parsimony, as a functional component of the scientists heuristic repertoire, is only useful when distinguishing between two competing explanations of more or less equal empirical content. In such cases parsimony dictates that researchers reject the explanation with the most ad hoc elements, a stricture that is still useful for archaeology – no matter how complex the phenomena in question turn out to be.

References:

Hull, David L. 2001. Science and Selection: Essays on Biological Evolution and the Philosphy of Science. Cambridge: Cambridge University Press

Hull, David L. 1988. Science as a Process: An Evolutionary Account of the Social and Conceptual Development of Science. Chicago, IL: University of Chicago Press

Kuhn, Thomas S. (2012) The Structure of Scientific Revolutions: 50^th Anniversary Edition. Chicago, IL: University of Chicago Press.

Kuhn, Thomas S. (1970) Logic of discovery or psychology of research? In I. Lakatos & A. Musgrave (Eds.) Criticisms and the Growth of Knowledge (pp. 4-10) Cambridge: Cambrdige Univeristy Press.

Lakatos, Imre. (1977) Science and pseudoscience. Philosophical Papers, vol. 1. (pp. 1-7). Cambridge: Cambridge University Press.

Maxwell, Nicholas. (1974) “The Rationality of Scientific Discovery”, Philosophy of Science 41,

295. 123-153 and 247-295.

Popper, Karl. (2002) The Logic of Scientific Discovery. New York, NY: Routledge

Popper, Karl. (1963) Conjectures and Refutations. London: Routledge & Kegan Paul.

Thagard, Paul R. (1978) Why astrology is a pseudoscience. In P. Asquith & I. Hacking (Eds.) Proceedings of the Philosophy of Science Association, Vol. 1. (pp. 223-34). East Lansing, MI; Philosophy of Science Association.

This review was initially produced a few months back for an archaeological theory class. Considering how good I thought Trigger’s work was, I thought I would make my opinions available online – albeit in slightly modified form.