Inferences from the absence of evidence to something are common in ordinary speech, but when used in scientific argumentations are usually considered deficient or outright false. Yet, as demonstrated here with the help of various examples, archaeologists frequently use inferences and reasoning from absence, often allowing it a status on par with inferences from tangible evidence. This discrepancy has not been examined so far. The article analyses it drawing on philosophical discussions concerning the validity of inference from absence, using probabilistic (...) models that were originally developed to show that such inferences are weak and inconclusive. The analysis reveals that inference from absence can indeed be justified in many important situations of archaeological research, such as excavations carried out to explore the past existence and time-span of sedentary human habitation. The justification is closely related to the fact that archaeology explores the human past via its material remains. The same analysis points to instances where inference from absence can have comparable validity in other historical sciences, and to research questions in which archaeological inference from absence will be problematic or totally unwarranted. (shrink)

This article examines the effect of material evidence upon historiographic hypotheses. Through a series of successive Bayesian conditionalizations, I analyze the extended competition among several hypotheses that offered different accounts of the transition between the Bronze Age and the Iron Age in Palestine and in particular to the “emergence of Israel”. The model reconstructs, with low sensitivity to initial assumptions, the actual outcomes including a complete alteration of the scientific consensus. Several known issues of Bayesian confirmation, including the problem of (...) old evidence, the introduction and confirmation of novel theories and the sensitivity of convergence to uncertain and disputed evidence are discussed in relation to the model’s result and the actual historical process. The most important result is that convergence of probabilities and of scientific opinion is indeed possible when advocates of rival hypotheses hold similar judgment about the factual content of evidence, even if they differ sharply in their historiographic interpretation. This speaks against the contention that understanding of present remains is so irrevocably biased by theoretical and cultural presumptions as to make an objective assessment impossible. (shrink)

Several scholars observed that narratives about the human past are evaluated comparatively. Few attempts have been made, however, to explore how such evaluations are actually done. Here I look at a lengthy “contest” among several historiographic narratives, all constructed to make sense of another one—the biblical story of the conquest of Canaan. I conclude that the preference of such narratives can be construed as a rational choice. In particular, an easily comprehensible and emotionally evocative narrative will give way to a (...) complex and mundane one, when the latter provides a more coherent account of the consensually accepted body of evidence. This points to a fundamental difference between historiographic narratives and fiction, contrary to some influential opinions in the philosophy of historiography. Such historiographic narratives have similarities with hypotheses and narrative explanations in natural science. (shrink)

This treatise covers the history, now more than 170 years long, of researches and debates concerning the biblical city of Ai. This archetypical chapter in the evolution of biblical archaeology and historiography was never presented in full. I use the historical data as a case study to explore a number of epistemological issues, such as the creation and revision of scientific knowledge, the formation and change of consensus, the Kuhnian model of paradigm shift, several models of discrimination between hypotheses about (...) the past, the interplay between scientists' values and their epistemic beliefs, and the truth-bearing of historiographic reconstruction. I show, in particular, that when scientists share common epistemic values they can modify their beliefs even when such changes go against deeply entrenched biases and preconceptions. Considerations of coherence usually constrain such modifications, and when sufficient data is available the result can be a profound change of beliefs. Several episodes of the "Ai debates" demonstrate, however, that similar change of beliefs will not occur when non-epistemic values take precedence. (shrink)

I propose a framework, derived from moral theory, for assessing the moral status of intelligent machines. Using this framework, I claim that some current and foreseeable intelligent machines have approximately as much moral status as plants, trees, and other environmental entities. This claim raises the question: what obligations could a moral agent (e.g., a normal adult human) have toward an intelligent machine? I propose that the threshold for any moral obligation should be the "functional morality" of Wallach and Allen (...) [20], while the upper limit of our obligations should not exceed the upper limit of our obligations toward plants, trees, and other environmental entities. (shrink)

hroughout medieval Christianity, religious works of art emerged to illustrate the teachings of the Bible for the largely illiterate population. What, then, is the significance of the psychoactive mushrooms hiding in plain sight in the artwork and icons of many European and Middle-Eastern churches? Does Christianity have a psychedelic history? -/- Providing stunning visual evidence from their anthropological journey throughout Europe and the Middle East, including visits to Roslyn Chapel and Chartres Cathedral, authors Julie and Jerry Brown document the (...) role of visionary plants in Christianity. They retrace the pioneering research of R. Gordon Wasson, the famous “sacred mushroom seeker,” on psychedelics in ancient Greece and India, and among the present-day reindeer herders of Siberia and the Mazatecs of Mexico. Challenging Wasson’s legacy, the authors reveal his secret relationship with the Vatican that led to Wasson’s refusal to pursue his hallucinogen theory into the hallowed halls of Christianity. -/- Examining the Bible and the Gnostic Gospels, the authors provide scriptural support to show that sacred mushrooms were the inspiration for Jesus’ revelation of the Kingdom of Heaven and that he was initiated into these mystical practices in Egypt during the Missing Years. They contend that the Trees of Knowledge and of Immortality in Eden were sacred mushrooms. -/- Uncovering the role played by visionary plants in the origins of Judeo-Christianity, the authors invite us to rethink what we know about the life of Jesus and to consider a controversial theory that challenges us to explore these sacred pathways to the divine. (shrink)