Recent research has shown that human instrumental action is associated with systematic changes in time perception: The interval between a voluntary action and an outcome is perceived as shorter than the interval between a physically similar involuntary movement and an outcome. The study by, Ebert and Wegner suggests that this change in time perception is related to higher order agency experience. Notwithstanding certain issues arising from their study, which are discussed, we believe it offers validation of binding as a (...) measure of sense of agency. (shrink)

At least since Aristotle’s famous 'sea-battle' passages in On Interpretation 9, some substantial minority of philosophers has been attracted to the doctrine of the open future--the doctrine that future contingent statements are not true. But, prima facie, such views seem inconsistent with the following intuition: if something has happened, then (looking back) it was the case that it would happen. How can it be that, looking forwards, it isn’t true that there will be a sea battle, while also being true (...) that, looking backwards, it was the case that there would be a sea battle? This tension forms, in large part, what might be called the problem of future contingents. A dominant trend in temporal logic and semantic theorizing about future contingents seeks to validate both intuitions. Theorists in this tradition--including some interpretations of Aristotle, but paradigmatically, Thomason (1970), as well as more recent developments in Belnap, et. al (2001) and MacFarlane (2003, 2014)--have argued that the apparent tension between the intuitions is in fact merely apparent. In short, such theorists seek to maintain both of the following two theses: (i) the open future: Future contingents are not true, and (ii) retro-closure: From the fact that something is true, it follows that it was the case that it would be true. It is well-known that reflection on the problem of future contingents has in many ways been inspired by importantly parallel issues regarding divine foreknowledge and indeterminism. In this paper, we take up this perspective, and ask what accepting both the open future and retro-closure predicts about omniscience. When we theorize about a perfect knower, we are theorizing about what an ideal agent ought to believe. Our contention is that there isn’t an acceptable view of ideally rational belief given the assumptions of the open future and retro-closure, and thus this casts doubt on the conjunction of those assumptions. (shrink)

Mountaineering is a dangerous activity. For many mountaineers, part of its very attraction is the risk, the thrill of danger. Yet mountaineers are often regarded as reckless or even irresponsible for risking their lives. In this paper, we offer a defence of risk-taking in mountaineering. Our discussion is organised around the fact that mountaineers and non-mountaineers often disagree about how risky mountaineering really is. We hope to cast some light on the nature of this disagreement – and to argue that (...) mountaineering may actually be worthwhile because of the risks it involves. Section 1 introduces the disagreement and, in doing so, separates out several different notions of risk. Sections 2–4 then consider some explanations of the disagreement, showing how a variety of phenomena can skew people's risk judgements. Section 5 then surveys some recent statistics, to see whether these illuminate how risky mountaineering is. In light of these considerations, however, we suggest that the disagreement is best framed not simply in terms of how risky mountaineering is but whether the risks it does involve are justified. The remainder of the paper, sections 6–9, argues that risk-taking in mountaineering often is justified – and, moreover, that mountaineering can itself be justified by and because of the risks it involves. (shrink)

Profoundly important ethical and political controversies turn on the question of whether biological life is an essential aspect of a human person, or only an extrinsic instrument. Lee and George argue that human beings are physical, animal organisms - albeit essentially rational and free - and examine the implications of this understanding of human beings for some of the most controversial issues in contemporary ethics and politics. The authors argue that human beings are animal organisms and that their personal identity (...) across time consists in the persistence of the animal organisms they are; they also argue that human beings are essentially rational and free and that there is a radical difference between human beings and other animals; criticize hedonism and hedonistic drug-taking; present detailed defenses of the prolife positions on abortion and euthanasia; and defend the traditional moral position on marriage and sexual acts. (shrink)

Virtue ethics seems to be a promising moral theory for understanding and interpreting the development and behavior of artificial moral agents. Virtuous artificial agents would blur traditional distinctions between different sorts of moral machines and could make a claim to membership in the moral community. Accordingly, we investigate the “machine question” by studying whether virtue or vice can be attributed to artificial intelligence; that is, are people willing to judge machines as possessing moral character? An experiment describes situations where either (...) human or AI agents engage in virtuous or vicious behavior and experiment participants then judge their level of virtue or vice. The scenarios represent different virtue ethics domains of truth, justice, fear, wealth, and honor. Quantitative and qualitative analyses show that moral attributions are weakened for AIs compared to humans, and the reasoning and explanations for the attributions are varied and more complex. On “relational” views of membership in the moral community, virtuous machines would indeed be included, even if they are indeed weakened. Hence, while our moral relationships with artificial agents may be of the same types, they may yet remain substantively different than our relationships to human beings. (shrink)

Die ZKph im Gespräch mit Johannes Ebert, Generalsekretär des Goethe-Instituts.

Epistemic contextualism is a recent and hotly debated position. In its dominant form, EC is the view that the proposition expressed by a given knowledge sentence depends upon the context in which it is uttered. What makes this view interesting and controversial is that ‘context’ here refers, not to certain features of the putative subject of knowledge or his/her objective situation, but rather to features of the knowledge attributor' psychology and/or conversational-practical situation. As a result of such context-dependence, utterances of (...) a given such sentence, made in different contexts, may differ in truth value. (shrink)

Roughly, animalism is the doctrine that each of us is identical with an organism. This paper explains and defends a hylemorphic version of animalism. I show how hylemorphic animalism handles standard objections to animalism in compelling ways. I also show what the costs of endorsing hylemorphic animalism are. The paper's contention is that despite the costs, the view is worth taking seriously.

The logic of ‘being informed’ gives a formal analysis of a cognitive state that does not coincide with either belief, or knowledge. To Floridi, who first proposed the formal analysis, the latter is supported by the fact that unlike knowledge or belief, being informed is a factive, but not a reflective state. This paper takes a closer look at the formal analysis itself, provides a pure and an applied semantics for the logic of being informed, and tries to find out (...) to what extent the formal analysis can contribute to an information-based epistemology. (shrink)

The notion of mutual aid, which Peter Kropotkin introduced in the 19th century, goes against the logic of competition as a natural condition, and instead shows how mutual aid is a more important factor to consider for the survival and flourishing of a group. The best cooperation strategies allow organisms to adapt to different types of changes in their environment—and we have witnessed a lot of these changes since the start of the COVID‐19 pandemic. This propensity towards cooperation is not (...) a foreign concept, despite how it seems to be overshadowed by individualism in Western societies. These reflections then lead us to believe it is possible to apply the anarchist philosophical principle of mutual aid to our social organizations, rather than giving priority, again and again, to competition and professional hierarchies, especially in healthcare systems, and particularly in hospitals were the majority of nurses work. For us, anarchist philosophical precepts, including but not limited to mutual aid, can be the key to a more adequate functioning of healthcare institutions. Anarchism can help to imagine the first steps needed to take to gradually move away from ideologies that encourage competition, professional hierarchies, and illegitimate authority. In this paper, we will first explore some anarchist philosophical precepts before turning to mutual aid as it is currently conceptualised, then highlight several concrete ways it is visible in nursing, as well as ways it can be applied in hospitals, and healthcare systems. (shrink)

Machine learning researchers distinguish between reinforcement learning and supervised learning and refer to reinforcement learning systems as “agents”. This paper vindicates the claim that systems trained by reinforcement learning are agents while those trained by supervised learning are not. Systems of both kinds satisfy Dretske’s criteria for agency, because they both learn to produce outputs selectively in response to inputs. However, reinforcement learning is sensitive to the instrumental value of outputs, giving rise to systems which exploit the effects of outputs (...) on subsequent inputs to achieve good performance over episodes of interaction with their environments. Supervised learning systems, in contrast, merely learn to produce better outputs in response to individual inputs. (shrink)

ABSTRACT This article defends the following argument: what makes you and I valuable so that it is wrong to kill us now is what we are (essentially). But we are essentially physical organisms, who, embryology reveals, came to be at conception/fertilisation. I reply to the objection to this argument (as found in Dean Stretton, Judith Thomson, and Jeffrey Reiman), which holds that we came to be at one time, but became valuable as a subject of rights only some time later, (...) in virtue of an acquired characteristic. I argue against this position that the difference between a basic, natural capacity and some degree of development of such a capacity is a mere difference in degree, that this position logically implies the denial of equal personal dignity, and that the selection of the required degree of development of a capacity is necessarily arbitrary. (shrink)

Abstract: There is no such thing as ‘the’ hylemorphic account of personal identity. There are several views that count as hylemorphic, and these views can be grouped into two main families—the corruptionist view, and the survivalist view. The differentiating factor is that the corruptionist view holds that the persistence of the soul is not sufficient for the persistence of the person, while the survivalist view holds that the persistence of the soul is sufficient for the persistence of the person. In (...) this paper, I argue that hylemorphists should prefer the corruptionist view. This project ought to be of interest to anyone working on issues of personal identity, not only because hylemorphic views are historically important, but also because they are currently receiving significant attention in the personal identity literature. (shrink)

Kant famously insisted that “the idea of the will of every rational being as a universally legislative will” is the supreme principle of morality. Recent interpreters have taken this emphasis on the self-legislation of the moral law as evidence that Kant endorsed a distinctively constructivist conception of morality according to which the moral law is a positive law, created by us. But a closer historical examination suggests otherwise. Kant developed his conception of legislation in the context of his opposition to (...) theological voluntarist accounts of morality and his engagement with conceptions of obligation found in his Wolffian predecessors. In order to defend important claims about the necessity and immediacy of moral obligation, Kant drew and refined a distinction between the legislation and authorship of the moral law in a way that precludes standard theological voluntarist theories and presents an obstacle to recent constructivist interpretations. A correct understanding of Kant's development and use of this distinction reveals that his conception of legislation leaves little room for constructivist moral anti-realism. (shrink)

D. Alan Shewmon has advanced a well-documented challenge to the widely accepted total brain death criterion for death of the human being. We show that Shewmon's argument against this criterion is unsound, though he does refute the standard argument for that criterion. We advance a distinct argument for the total brain death criterion and answer likely objections. Since human beings are rational animals – sentient organisms of a specific type – the loss of the radical capacity for sentience involves a (...) substantial change, the passing away of the human organism. In human beings total brain death involves the complete loss of the radical capacity for sentience, and so in human beings total brain death is death. (shrink)

One set of neglected problems consists of paradoxes of omniscience clearly recognizable as forms of the Liar, and these I have never seen raised at all. Other neglected problems are difficulties for omniscience posed by recent work on belief de se and essential indexicals. These have not yet been given the attention they deserve.

Let R(X, B) denote the class of probability functions that are defined on algebra X and that represent rationally permissible degrees of certainty for a person whose total relevant background evidence is B. This paper is concerned with characterizing R(X, B) for the case in whichX is an algebra of propositions involving two properties and B is empty. It proposes necessary conditions for a probability function to be in R(X, B), some of which involve the notion of statistical dependence. The (...) class of probability functions that satisfy these conditions, here denoted PI, includes a class that Carnap once proposed for the same situation. Probability functions in PI violate Carnap's axiom of analogy but, it is argued, that axiom should be rejected. A derivation of Carnap's model by Hesse has limitations that are not present in the derivation of PI given here. Various alternative probability models are considered and rejected. (shrink)

This paper reviews the largely psychological literature surrounding apparent failures of human rationality (sometimes referred to as 'the Rationality Wars') and locates it with respect to concepts and issues within more traditional epistemological inquiry. The goal is to bridge the gap between these two large and typically disconnected literatures – concerning rationality and the psychology of human reasoning, on the one hand, and epistemological theories of justified or rational belief, on the other – and to do so in such as (...) way as to expose interesting points of contact and convergence between them. (shrink)

Central to the contemporary dispute over 'naturalizing epistemology' is the question of the continuity of epistemology with science, i.e., how far purely descriptive, psychological matters can or should inform the traditional evaluative epistemological enterprise. Thus all parties tend to agree that the distinction between psychology and epistemology corresponds to a firm fact/value distinction. This is something Reid denies with respect to the first principles of common sense: while insisting on the continuity of epistemology with the rest of science, he does (...) not wish to derive an 'ought' from an 'is', nor to reduce the epistemological to the psychological. His view is that the first principles are constitutive principles, hence that they are simultaneously descriptive and prescriptive, and thus that with regard to them there is in this sense simply no fact/value gap to be bridged. (shrink)

There is an important disagreement in contemporary epistemology over the possibility of non-epistemic reasons for belief. Many epistemologists argue that non-epistemic reasons cannot be good or normative reasons for holding beliefs: non-epistemic reasons might be good reasons for a subject to bring herself to hold a belief, the argument goes, but they do not offer any normative support for the belief itself. Non-epistemic reasons, as they say, are just the wrong kind of reason for belief. Other epistemologists, however, argue that (...) there can be cases where non-epistemic reasons directly offer normative support for the beliefs a subject holds. -/- My aim in this paper is to remove an apparent obstacle for the view that there can be non-epistemic normative reasons for belief, by showing that the existence of non-epistemic reasons for belief does not conflict with epistemic standards for the assessment of inference. More specifically, I aim to show that the following principles are compatible: -/- Epistemic Norm of Inference (ENI): Necessarily, for all subjects, S, and inferences, I: I is a good inference for S only if S can gain a (doxastically) epistemically justified belief in I’s conclusion on the basis of I’s premises. -/- Non-Epistemic Reasons for Belief (NERB): Possibly, for some subject, S, reason, R, and belief, B: R is a good (i.e., normative) reason for S to hold B, and R is not an epistemic reason for B. -/- Guidance: For all subjects S, potential reasons R, and beliefs/actions φ: In order for R to count as a normative reason for S to φ, it must be possible for S to take R into account as relevant to the determination of whether S ought to φ. -/- One might naturally think that these principles conflict, for if there are non-epistemic reasons for belief, then they must guide deliberation, and in guiding deliberation, they would violate epistemic standards. The aim of this paper is to show that no such conflict need arise. -/- Section 2 of the paper proceeds to set out the concept of an inference, and to sketch an epistemic framework for the assessment of inferences and arguments. Section 3 sets out the distinction between normative and motivating reasons, and briefly defends the view that there can be non-epistemic reasons for beliefs. Section 4 shows that non-epistemic reasons for belief are compatible with epistemic standards for inference, because any time a reason R is a good non-epistemic reason for a subject S to hold a belief B, there is an epistemically good inference available to S which takes R as a premise and which concludes with the meta-belief that S ought to hold B. So the paper employs a level-connecting principle between normative reasons for φ-ing and epistemic reasons for believing that one ought to φ. The paper ends with clarifications of that level-connecting principle, and responses to three objections. (shrink)

Animalism is the doctrine that you and I are animals. Like any substantive philosophical position, animalism faces objections. For example, imagine a case of conjoined twins, where there are two heads, but only one “body,” and where each head seems to have its own typically human and fully discrete mental life. It would be natural to assume that each of the twins is a thing like you and me—each twin is one of us. But it appears that each twin cannot (...) be a distinct human animal, since it appears in this case that there is only one animal. So it appears that animalism renders the wrong verdict in this case. I present two responses to this worry, drawing on Aristotelian claims about the centrality of sensation to animals, and on an account of organism-hood from Maureen and Samuel Condic. I close by considering craniopagus parasiticus and cephalopagus, and show the Aristotelian response is effective in such cases as well. (shrink)

I develop and refine an argument for the total brain death criterion of death previously advanced by Germain Grisez and me: A human being is essentially a rational animal, and so must have a radical capacity for rational operations. For rational animals, conscious sensation is a pre-requisite for rational operation. But total brain death results in the loss of the radical capacity for conscious sensation, and so also for rational operations. Hence, total brain death constitutes a substantial change—the ceasing to (...) be of the human being. Objections are considered, including the objection that total brain death need not result in the loss of capacity for sensation, and that damage to the brain less than total brain death can result in loss of capacity for rational operations. (shrink)

Some claim Kant’s commitment to the explanatory priority of judgments over concepts is one of his most important contributions to the philosophy of mind. There is, however, extensive disagreement over the nature and extent of this commitment. Existing interpretations ignore a substantial body of textual evidence and offer no account of the origins of Kant’s view. This paper corrects for these deficiencies. I explain, first, the relevant accounts of concept possession Kant encountered in the writings of his predecessors; and, second, (...) how within this context he first expressed a commitment to the view that conceptual content is explanatorily dependent on acts of judgment. I then argue that Kant endorsed a second form of discursive primacy, namely, the view that every use of a concept in conscious thought about an object has the form of a judgment. (shrink)

This article outlines the emergence of ABA (Applied Behaviour Analysis) in the mid-20th century, and the current popularity of ABA in the anglophone world. I draw on the work of earlier historians to highlight the role of Ole Ivar Lovaas, the most influential practitioner of ABA. I argue that reception of his initial work was mainly positive, despite concerns regarding its efficacy and use of physical aversives. Lovaas’ work, however, was only cautiously accepted by medical practitioners until he published results (...) in 1987. Many accepted the results as validation of Lovaas’ research, though both his methods and broader understanding of autism had shifted considerably since his early work in the 1960s. The article analyses the controversies surrounding ABA since the early 1990s, considering in particular criticisms made by autistic people in the ‘neurodiversity movement’. As with earlier critics, some condemn the use of painful aversives, exemplified in the campaign against the use of shock therapy at the Judge Rotenberg Center. Unlike earlier, non-autistic critics, however, many in this movement reject the ideological goals of ABA, considering autism a harmless neurological difference rather than a pathology. They argue that eliminating benign autistic behaviour through ABA is impermissible, owing to the individual psychological harm and the wider societal impact. Finally, I compare the claims made by the neurodiversity movement with those made by similar 20th- and 21st-century social movements. (shrink)

This paper presents an account of the nature of desire, informed by psychology and neuroscience, which entails that hunger is not a desire. The account is contrasted with Schroeder’s well-known empirically-informed theory of desire. It is argued that one significant virtue of the present account, in comparison with Schroeder’s theory, is that it draws a sharp distinction between desires and basic drives, such as the drive for food. One reason to draw this distinction is that experiments on incentive learning show (...) that desires and basic drives influence action in different ways. (shrink)

The Law of Non-Contradiction holds that both sides of a contradiction cannot be true. Dialetheism is the view that there are contradictions both sides of which are true. Crucial to the dispute, then, is the central notion of contradiction. My first step here is to work toward clarification of that simple and central notion: Just what is a contradiction?

In various places we have defended the position that a new human organism, that is, an individual member of the human species, comes to be at fertilization, the union of the spermatozoon and the oocyte. This individual organism, during the ordinary course of embryological development, remains the same individual and does not undergo any further substantial change, unless monozygotic twinning, or some form of chimerism occurs. Recently, in this Journal Jason Morris has challenged our position, claiming that recent findings in (...) reproductive and stem cell biology have falsified our view. He objects to our claim that a discernible substantial change occurs at conception, giving rise to the existence of a new individual of the human species. In addition, he objects to our claim that the embryo is an individual, a unified whole that persists through various changes, and thus something other than a mere aggregate of cells. Morris raises a number of objections to these claims. However, we will show that his arguments overlook key data and confuse biological, metaphysical, and ethical questions. As a result, his attempts to rebut our arguments fail. (shrink)

This paper argues that it is permissible for computer scientists and engineers—working with advanced militaries that are making good faith efforts to follow the laws of war—to engage in the research and development of lethal autonomous weapons systems. Research and development into a new weapons system is permissible if and only if the new weapons system can plausibly generate a superior risk profile for all morally relevant classes and it is not intrinsically wrong. The paper then suggests that these conditions (...) are satisfied by at least some potential LAWS development programs. More specifically, since LAWS will lead to greater force protection, warfighters are free to become more risk-acceptant in protecting civilian lives and property. Further, various malicious motivations that lead to war crimes will not apply to LAWS or will apply to no greater extent than with human warfighters. Finally, intrinsic objections—such as the claims that LAWS violate human dignity or that it creates ‘responsibility gaps’—are rejected on the basis that they rely upon implausibly idealized and atomized understandings of human decision-making in combat. (shrink)

The determination of individual moral status is a central factor in the ethical evaluation of controversial practices such as elective abortion, human embryo-destructive research, and the care of the severely disabled and those in persistent vegetative states. A review of recent work on Kant reveals the need for a careful examination of the content of Kant ’s biological and psychological theories and their relation to his views about moral status. Such an examination, in conjunction with Kant ’s practical-metaphysical analysis of (...) the origins of freedom, reveals Kant ’s principled basis for his contention that all human beings possess moral status. (shrink)

First and still only philosophy treatise on drawing, explaining the bases of meaning in all kinds of drawings, including technical and informational, design, child, and art drawings--depictive and nondepictive, East and West--engaging cognitive and developmental psychology, philosophy, art history and criticism. Ca 290 double-columned pp., 92 illus. Reviews include: Philosophy--David Hills, Journal of Aesthetics and Art Criticism 65, no. 2 (Spring 2007): 235-237. Aesthetics--Michael Podro, British Journal of Aesthetics 48, no. 3 (July 2008): 346-347. Art history--Svetlana Alpers, Phi Bet Kappa (...) Society Key Reporter (Summer 2006): 14 http://www.pbk.org/documents/tkrpdf/TKRSummer2006.pdf. General--Amy Ione, Leonardo On-line Reviews: http://www.leonardo.info/reviews/jan2007/draw_ione.html . (shrink)

By resituating Alexander von Humboldt in the “working world” of mining, this essay offers a case study of the way in which industry has shaped practice and theory in the history of science. While Humboldt’s experience as a miner in Saxony and Prussia provided him a venue in which to study fossilized vegetation, revealing a fundamental link between the migrations of plants and of peoples, industrial concerns about miners’ safety inspired a study of the interplay between plants and people that (...) shaped his later articulation of the verticality of plant distribution. Moreover, the cartographic methods Humboldt employed during his American journey depended as much on drawing practices indebted to mining as they did on patterns of vertical mobility above and below the surface of the earth. These arguments ultimately encourage a departure from “Humboldtian Science,” a term that has veiled an originally Prusso-Saxon science beneath a set of Anglo-American connotations. (shrink)

I offer a novel solution to Zeno’s paradox of The Arrow by introducing nilpotent infinitesimal lengths of time. Nilpotents are nonzero numbers that yield zero when multiplied by themselves a certain number of times. Zeno’s Arrow goes like this: during the present, a flying arrow is moving in virtue of its being in flight. However, if the present is a single point in time, then the arrow is frozen in place during that time. Therefore, the arrow is both moving and (...) at rest. In “Zeno’s Arrow, Divisible Infinitesimals, and Chrysippus,” White suggests using an infinitesimal value as the length of the present. Contra Zeno, this allows the arrow to be moving in the present, rather than frozen in place. In this paper, I follow the basic outline of White’s solution but argue that his solution suffers from arbitrariness and a related theoretical artificiality in relation to the system of infinitesimals he invokes, viz. in relation to the hyperreal infinitesimals of nonstandard analysis. After arguing that any solution to the paradox must satisfy certain theoretical requirements, I examine White’s solution alongside two nilpotent solutions. One of these solutions is inspired by F.W. Lawvere’s Smooth Infinitesimal Analysis and the other is inspired by Paolo Giordano’s ring of Fermat Reals. I argue that Giordano’s nilpotents supply the best answer to Zeno’s paradox. (shrink)

The notion of risk plays a central role in economics, finance, health, psychology, law and elsewhere, and is prevalent in managing challenges and resources in day-to-day life. In recent work, Duncan Pritchard (2015, 2016) has argued against the orthodox probabilistic conception of risk on which the risk of a hypothetical scenario is determined by how probable it is, and in favour of a modal conception on which the risk of a hypothetical scenario is determined by how modally close it is. (...) In this article, we use Pritchard’s discussion as a springboard for a more wide-ranging discussion of the notion of risk. We introduce three different conceptions of risk: the standard probabilistic conception, Pritchard’s modal conception, and a normalcy conception that is new (though it has some precursors in the psychological literature on risk perception). Ultimately, we argue that the modal conception is ill-suited to the roles that a notion of risk is required to play and explore the prospects for a form of pluralism about risk, embracing both the probabilistic and the normalcy conceptions. (shrink)

Berichte zur Wissenschaftsgeschichte, EarlyView.

This paper explores themethodological consequences of AmericanPragmatism for the social sciences. It alsocriticises some rival perspectives onmethodology of social research, in particularfalsificationist, realist and someanti-naturalist views. It is argued thatAmerican Pragmatism shows striking affinitieswith the genealogical method of history and thereflexive turn in cultural anthropology. It isalso argued that Pragmatism forces us to thinkdifferently about the relationship betweentheory and empirical research.

In this paper, missing attribute values in incomplete data sets have three possible interpretations: lost values, attribute-concept values and ‘do not care’ conditions. For rule induction, we use characteristic sets and generalized maximal consistent blocks. Therefore, we apply six different approaches for data mining. As follows from our previous experiments, where we used an error rate evaluated by ten-fold cross validation as the main criterion of quality, no approach is universally the best. Thus, we decided to compare our six approaches (...) using complexity of rule sets induced from incomplete data sets. We show that the smallest rule sets are induced from incomplete data sets with attribute-concept values, while the most complicated rule sets are induced from data sets with lost values. The choice between interpretations of missing attribute values is more important than the choice between characteristic sets and generalized maximal consistent blocks. (shrink)