Black Ravens Research Articles

Dasgupta's Detonation

Dasgupta's Detonation

«Черные вороны»: конфликт духовенства и театрального сообщества (1907 г.)

«Черные вороны»: конфликт духовенства и театрального сообщества (1907 г.)

A MORE DEVASTATING VERSION OF THE RAVEN PARADOX

Hempel's famous Raven Paradox derives from Nicod's criteria for confirmation and the Equivalence Condition, the unintuitive conclusion that things like white roses, green T-shirts and ice cubes confirm the raven hypothesis ‘All ravens are black.’ By a small rearrangement of the Equivalence Condition, I show that we can also derive the conclusion, which sounds even more intuitively intolerable, that observation of black ravens fails to confirm the raven hypothesis. We are left with the contradictory result that black ravens both confirm and do not confirm the raven hypothesis.

A New Bayesian Solution to the Paradox of the Ravens

The canonical Bayesian solution to the ravens paradox faces a problem: it entails that black nonravens disconfirm the hypothesis that all ravens are black. I provide a new solution that avoids this problem. On my solution, black ravens confirm that all ravens are black, while nonblack nonravens and black nonravens are neutral. My approach is grounded in certain relations of epistemic dependence, which, in turn, are grounded in the fact that the kind raven is more natural than the kind black. The solution applies to any generalization “All F’s are G” in which F is more natural than G.

A Philosophical Treatise of Universal Induction

Understanding inductive reasoning is a problem that has engaged mankind for thousands of years. This problem is relevant to a wide range of fields and is integral to the philosophy of science. It has been tackled by many great minds ranging from philosophers to scientists to mathematicians, and more recently computer scientists. In this article we argue the case for Solomonoff Induction, a formal inductive framework which combines algorithmic information theory with the Bayesian framework. Although it achieves excellent theoretical results and is based on solid philosophical foundations, the requisite technical knowledge necessary for understanding this framework has caused it to remain largely unknown and unappreciated in the wider scientific community. The main contribution of this article is to convey Solomonoff induction and its related concepts in a generally accessible form with the aim of bridging this current technical gap. In the process we examine the major historical contributions that have led to the formulation of Solomonoff Induction as well as criticisms of Solomonoff and induction in general. In particular we examine how Solomonoff induction addresses many issues that have plagued other inductive systems, such as the black ravens paradox and the confirmation problem, and compare this approach with other recent approaches.

Inductive Influence

Objective Bayesianism has been criticised for not allowing learning from experience: it is claimed that an agent must give degree of belief 12 to the next raven being black, however many other black ravens have been observed. I argue that this objection can be overcome by appealing to objective Bayesian nets, a formalism for representing objective Bayesian degrees of belief. Under this account, previous observations exert an inductive influence on the next observation. I show how this approach can be used to capture the Johnson–Carnap continuum of inductive methods, as well as the Nix–Paris continuum, and show how inductive influence can be measured. 1. Introduction2. The Problem3. Diagnosis4. Objective Bayesian Nets5. Resolution6. The Johnson–Carnap Continuum7. The Nix–Paris Continuum8. Linguistic Slack9. Frequencies and Degrees of Belief10. Conclusion

BLACKOUT: Utopian Technologies in Adrienne Kennedy's Funnyhouse of a Negro

In the second-to-last episode of Funnyhouse of a Negro, Adrienne Kennedy asks for the impossible. The oxymoronic effect of "a dark brightness" lies outside the realm of the technically possible. What combinations of lights, gels. and focus techniques might create "a dark brightness"? The requirement of "brightness" eliminates the possibility of "dark." This example is not the first time in her 1964 one-act that Kennedy requires the practically impossible. In her play, bald heads drop from the sky, black ravens fly around stage, walls appear out of nowhere and then characters walk through them. This is not to say that creative theatre professionals can't or won't come up with practical. elegant solutions to these staging problems. Indeed, Kennedy's impossible stage directions incite creative solutions, unique, unanticipated renderings of her imagined play in the material theatre. Nor is it to imply that the central work of theatre is to follow a playwright's stage directions as closely as possible. Creative solutions to impossible requirements include both "faithful" and "unfaithful" renderings. Rather, these impossible requirements highlight an impulse that lies at the core of theatrical representation: the impulse to substantiate or render the ideal. In the possibility that subtends that impulse is, I think, a utopic sensibility — a sense that something different or better could come out of current conditions.

The “raven paradox” in the light of probability theory

This paper deals with the well-known raven paradox, also named the paradox of black ravens, one of the most renowned paradoxes arising from the confirmation procedures for universal statements of empirical theories. Its aim is to show that the paradox owes its origin to a number of very drastic positions about the form in which such universal statements should be expressed, and the confirmation value the indirect observations (i.e., observations not explicitly carried out on ravens) should be deemed to have. More specifically, we suggest that the use of the formal language of calculus of predicates (and, correspondingly, of set theory) is uncorrect in the framework of empirical theories, and that, when using only statements about probabilities of events rather than about probabilities of truth of statements, and choosing a suitable confirmation procedure based on the law of large numbers, a comparison between the confirmation values of direct and indirect observations becomes clear and the paradox, at least as it has been described, disappears.

An analysis of bait-take and non-target impacts during a fox-control exercise

The effectiveness of a fox-control exercise at the Beecroft Peninsula, New South Wales, was evaluated by examining the change in proportion of baits taken during free-feeding and after lethal baiting in four different habitats (heath, forest, coastal scrub, beach), and the change in number of radio-collared foxes alive during the course of the baiting exercise. The change in proportion of baits taken by non-target species was also examined over the course of the study. Bait take declined by 97% from the initiation of poison baiting to the final day of poison baiting eight days later with significantly more baits being taken in heath than in any other habitat. Four out of six radio-collared foxes died on the first day of poison baiting while the other two foxes died within ten days of the start of the poison-baiting session. Black rats, currawongs and ravens took a small number of baits throughout the baiting exercise.

Black Ravens and a White Shoe

AbstractThis paper provides an explanation of why sightings of black ravens increase the degree of warranted belief in the proposition that all ravens are black, while observations of white shoes d...

White Swans, Black Ravens, and Lame Ducks: Necessary and Sufficient Causes in Epidemiology

Several authors have used Popper's "white swan" example to support arguments for a falsificationist approach to epidemiology. The statement "all swans are white" cannot be verified by finding even a large number of white swans, but can be falsified by finding a single black swan. An analogous epidemiologic example that has been proposed is the hypothesis that a particular virus is a necessary cause of acquired immunodeficiency syndrome (AIDS). Such examples, however, have little relevance to science since scientific theories are not generalizations of facts; rather, they involve an understanding of the underlying processes that cause certain facts to occur. Furthermore, the "white swan" example is particularly inapplicable to epidemiology, since most factors of scientific or public health importance are neither necessary nor sufficient causes of disease. Nevertheless, epidemiologic research has achieved success in the understanding and prevention of disease. These points are exemplified by applying Rothman's model of causal constellations, which provides a conceptual basis for the development of epidemiologic theories.

Popper on Scientific Statements

It is obvious that two contingent statements, each of which denies the existence of something, can be inconsistent with one another: for example, ‘There are no non-black ravens, and there is at least one raven’, and ‘There are no black ravens’. But it is also obvious that these two statements are inconsistent only because one of them, as well as denying the existence of something, asserts the existence of something. The mere denials of existence, ‘There are no non-black ravens’ and ‘There are no black ravens’, are consistent with one another. (Both of them would be true if there were no ravens at all.) Indeed, it must hold quite generally that two contingent statements cannot be inconsistent, where each is a mere denial of existence in the sense that it denies existence and does not also assert existence. For in order to be inconsistent with a mere denial of existence, a second statement must assert existence, whatever else it may do; and if it asserts existence, it is not itself a mere denial of existence.

Relevance and the Ravens

These are plausible statements of confirmation. But there is a general principle of confirmation, viz.: (3) Whatever confirms a given hypothesis also confirms any statement logically equivalent to it which is at least as plausible, but inconsistent with them. This fact constitutes the problem about the ravens. The most popular solution to this problem has been along the following. lines: that statement (i) is false; and that its plausibility is to be explained by the fact that, the world being as it actually is, evidence consisting of non-black non-ravens is more likely to be met with, and hence confirms 'All ravens are black' less, than the 'standard' evidence for it, viz. that which consists of black ravens.

Plankton and medical hydrobiology of tropical ponds with Daphnias and rotifers

Plankton and medical hydrobiology of tropical ponds with Daphnias and rotifers

CONFIRMATION BY OBSERVATION AND THE PARADOX OF THE RAVENS

that confirmation by observation requires that a prior condition be fulfilled in order that observations may have any power at all to confirm an hypothesis. This condition, which is rarely made explicit, pertains to the relation between the observational data and the permissible inductive inferences from the data; and its relevance to this paradox is that it is of such a nature that observations which may confirm one hypothesis will be entirely incapable of confirming certain logically equivalent, but nonetheless different hypotheses. If this view is correct, then the paradox can be resolved by rejecting the last of the three propositions which constitute it. Restating the problem, the paradox is derived from three propositions given as follows : 1 Prop. (I) Observations of black ravens confirm 'All ravens are black '.