Design explanation: determining the constraints on what can be alive

This paper is concerned with reasonings that purport to explain why certain organisms have certain traits by showing that their actual design is better than contrasting designs. Biologists call such reasonings ‘functional explanations’. To avoid confusion with other uses of that phrase, I call them ‘design explanations’. This paper discusses the structure of design explanations and how they contribute to scientific understanding. Design explanations are contrastive and often compare real organisms to hypothetical organisms that cannot possibly exist. They are not causal but appeal to functional dependencies between an organism’s different traits. These explanations point out that because an organism has certain traits (e.g., it lives on land), it cannot be alive if the trait to be explained (e.g., having lungs) were replaced by a specified alternative (e.g., having gills). They can be understood from a mechanistic point of view as revealing the constraints on what mechanisms can be alive.

The scientific use of ‘representation’ and ‘function’: avoiding explanatory vacuity

Nearly all of the ways philosophers currently attempt to define the terms ‘representation’ and ‘function’ undermine the scientific application of those terms by rendering the scientific explanations in which they occur vacuous. Since this is unacceptable, we must develop analyses of these terms that avoid this vacuity. Robert Cummins argues in this fashion in Representations, Targets, and Attitudes. He accuses ‘use theories’ of representational content of generating vacuous explanations, claims that nearly all current theories of representational content are use theories, and offers a non-use theory of representational content which avoids explanatory vacuity. One task I undertake in this article is to develop an alternative non-use theory which avoids an objection fatal to that theory. My second task is to adapt Cummins’ argument to criticize most current analyses of ‘function,’ which undermine scientific explanation in an analogous way. Though Cummins does not explicitly argue in this manner, his own analysis of ‘function,’ by avoiding any appeal to use, avoids the explanatory vacuity to which they succumb. Consequently, I endorse Cummins’ notion of function. However, although use theories fail as analyses of the terms ‘representation’ and ‘function,’ they can still make significant contributions to the sciences employing these terms. For, while philosophers seeking to define ‘representation’ and ‘function’ must avoid incorporating representational and functional uses into their definitions, scientists must still find a way to determine which representations and functions are being used. Suitably re-construed use theories of representation and function may in many cases assist them in this task.     

Mathematics and Program Explanations

Aidan Lyon has recently argued that some mathematical explanations of empirical facts can be understood as program explanations. I present three objections to his argument.     

疾病的进化论解释：——读《我们为什么生病》

现代医学重在对疾病的近因研究,而疾病的进化史原因,像机体设计上的缺陷,遗传基因与新环境因素的冲突,进化过程中病原同宿主的竞争等,却几乎完全被忽视。事实上,人类机体在漫长的进化过程中,每获得一种益处,几乎都要付出相应的代价,这就是相关的疾病。达尔文医学的新科学,这部全新视野的著作,全面地向人们展示了疾病的进化论解释,并正在创造其学术范式迥然不同的医学科学新领域。     

Truthmaker commitments

On the truthmaker view of ontological commitment [Heil (From an ontological point of view, 2003); Armstrong (Truth and truthmakers, 2004); Cameron (Philosophical Studies, 2008)], a theory is committed to the entities needed in the world for the theory to be made true. I argue that this view puts truthmaking to the wrong task. None of the leading accounts of truthmaking—via necessitation, supervenience, or grounding—can provide a viable measure of ontological commitment. But the grounding account does provide a needed constraint on what is fundamental. So I conclude that truthmaker commitments are not a rival to quantifier commitments, but a needed complement. The quantifier commitments are what a theory says exists, while the truthmaker commitments are what a theory says is fundamental.

Is backing grounding?

Separatists are grounding theorists who hold that grounding relations and metaphysical explanations are distinct, yet intimately connected in the sense that grounding relations back metaphysical explanations, just as causal relations back causal explanations. But Separatists have not elaborated on the nature of the ‘backing’ relation. In this paper, I argue that backing is a form of (partial) grounding. In particular, backing has many of the properties commonly attributed to grounding, and taking backing to be partial grounding allows Separatists to make the most of their position vis-à-vis their Unionist opponents.     

The expected likelihood of transitivity of preference

May's model of pairwise preference determination is used to assess the expected likelihood that a subject's pairwise preference comparisons on three alternatives will be transitive. A closed form representation for this expected likelihood is obtained for each situation considered. When the subject is assumed to act precisely according to rankings on attributes with May's model, the computed expected likelihoods the relatively large. When the subject becomes a probabilistic chooser, as defined in a specific manner, expected likelihoods of transitivity decrease significantly from corresponding values with May's model. For a probabilistic Chooser, there is a significant likelihood that the subject might yield transitive pairwise preferences substantially different than the results suggested by May's model.This research was supported by a grant from the General University Research Program and through a fellowship from the Center for Advanced Study, both of the University of Delaware. Very helpful input from John H. Antil, Meryl P. Gardner, and James M. Munch is also acknowledged.     

Simplicity and probability in causal explanation

What makes some explanations better than others? This paper explores the roles of simplicity and probability in evaluating competing causal explanations. Four experiments investigate the hypothesis that simpler explanations are judged both better and more likely to be true. In all experiments, simplicity is quantified as the number of causes invoked in an explanation, with fewer causes corresponding to a simpler explanation. Experiment 1 confirms that all else being equal, both simpler and more probable explanations are preferred. Experiments 2 and 3 examine how explanations are evaluated when simplicity and probability compete. The data suggest that simpler explanations are assigned a higher prior probability, with the consequence that disproportionate probabilistic evidence is required before a complex explanation will be favored over a simpler alternative. Moreover, committing to a simple but unlikely explanation can lead to systematic overestimation of the prevalence of the cause invoked in the simple explanation. Finally, Experiment 4 finds that the preference for simpler explanations can be overcome when probability information unambiguously supports a complex explanation over a simpler alternative. Collectively, these findings suggest that simplicity is used as a basis for evaluating explanations and for assigning prior probabilities when unambiguous probability information is absent. More broadly, evaluating explanations may operate as a mechanism for generating estimates of subjective probability.     

Absence Causation and a Liberal Theory of Causal Explanation

For the framework of event causation—i.e. the framework according to which causation is a relation between events—absences or omissions pose a problem. Absences, it is generally agreed, are not events; so, under the framework of event causation, they cannot be causally related. But, as a matter of fact, absences are often taken to be causes or effects. The problem of absence causation is thus how to make sense of causation that apparently involves absences as causes or effects. In an influential paper, Helen Beebee offers a partial solution to the problem by giving an account of causation by absence (i.e. causation in which absences are supposed to be causes). I argue that Beebee's account can be extended to cover causation of absence (i.e. causation in which absences are supposed to be effects) as well. More importantly, I argue that the extended Beebeeian account calls for a major modification to David Lewis's theory of causal explanation, usually taken as standard. Compared to the standard theory, the result of this modification, which I shall call ‘the liberal theory of causal explanation’, has, among other things, the advantage of being able to accommodate causal explanations in which the explananda are not given in terms of events.     

Explanatory warrant for scientific realism

Nancy Cartwright relies upon an inference pattern known as inference to the best causal explanation (IBCE) to support a limited form of entity realism, according to which we are warranted in believing in entities that purportively cause observable effects. IBCE, as usually understood, is valid, even though all other forms of inference to the best explanation (IBE) are usually understood to be invalid. We argue that IBCE and IBE are in the same boat with respect to their ability to support realist conclusions. Either rule can be interpreted as valid, this is a matter of semantic convention. However, doing so deprives the rule of the empirical content the realist needs, requiring the realist to find independent warrant for a strong (theoretical or causal) premise. We then examine the proposed means of obtaining this warrant, and find them as inadequate in the case of IBCE as they are in the case of IBE.     

The explanatory significance of wholes: How exclusive reliance on antecedent-consequent models of explanation undermines the study of persons

Psychology has long labored under a mechanistic view of persons as reducible to parts (i.e., traits) that dictate human functioning. Efforts to study persons holistically—as embodied wholes embedded in the world—have resuscitated the study of personhood and its development, overhauling linear cause-effect models of psychological functioning in favor of emergence-focused, dynamic process alternatives rooted in the concept of persons as necessarily constituted within interactive context. Focused on agency and self-determination, the study of personhood also calls for an appreciation of the explanatory significance of persons as persons, as unified wholes who preserve their own organization in the face of ceaseless exchange with the world. Fully adopting this important vantage point for understanding persons, however, is only possible by expanding notions of scientific explanation beyond the temporal framework of antecedent-consequent, parts-to-whole relations in order to embrace a person's wholeness itself as a legitimate mode of explanation for understanding functioning.     

神灵主义医学何以可能?

神灵主义医学,是人类历史上第一个医学范式,拥有一套完整的形而上学信念、方法论体系和解释机制。神灵主义医学已经长期存在,并且在当今世界也广泛存在,这是世界之中的事实,无需争论。站在当代医学发展的前沿回头看,神灵主义医学之所以能够长期指导人类的医疗实践,有其内在原因。人类的大量自限性疾病,为神灵主义医学的成功提供了广泛的归纳支持。安慰剂效应的发现,进一步揭示了神灵主义医学成功的内在可能性。超自然解释,是神灵主义医学治疗失败后,医师给予患者的无助安慰,却为巫医守住了信誉的最后堡垒。