Colour constancy refers to the ability to extract information about surface colours independently of illumination conditions. A ripe strawberry, for example, appears the same red when viewed under a blue sky or a reddish sunset. Since Land's pioneering work, discussion has centred on the issue whether colour constancy is achieved primarily in the retina or visual cortex. Recently, the debate has shifted to a consideration of the constraints imposed by various psychophysical tasks and instructions. Humans can judge illuminant colour, reflected-light (...) colour, surface colour, and the relationship between surface colours within a scene. Such observations suggest that colour constancy may not be a unitary phenomenon, and that its different aspects may be mediated at different levels in the visual system. Several questions therefore arise: are the tasks of surface estimation and illuminant estimation complementary, insofar as good performance in one implies poor performance in the other? How does retinal adaptation alter performance? Is colour vision tuned to the statistical composition of natural surfaces and illuminants? What role does colour-opponent processing in retina and cortex play in colour constancy? These and related questions are explored here in order to better understand what we mean when we ask: "Why do strawberries look red?". (shrink)

W. H. F. Barnes; XI*—Referring to Individuals, Proceedings of the Aristotelian Society, Volume 73, Issue 1, 1 June 1973, Pages 167–180, https://doi.org/10.1093/.

W. H. F. Barnes; XI*—Referring to Individuals, Proceedings of the Aristotelian Society, Volume 73, Issue 1, 1 June 1973, Pages 167–180, https://doi.org/10.1093/.

It is a widely held doctrine at the moment that metaphysical propositions are meaningless, are, in fact, not genuine propositions at all. This doctrine is supported by the contention that only propositions which are verifiable are significant: and it is held that metaphysical propositions do not fulfil this condition, and are consequently pseudo-propositions. Those who hold this view divide propositions into three classes: Tautologies; which are analytic, certain, and are guaranteed by the principle of contradiction. Factually significant propositions; which are (...) synthetic, hypothetical, and are capable of empirical verification. Pseudopropositions, which only appear to be propositions and are, in reality, meaningless nonsense. (shrink)

In accordance with Leo Strauss’s ingenious suggestion, the Athenian Stranger of Plato’s Laws is best understood as an alternative ‘Socrates’, fleeing from the hemlock to Crete. Situated between Crito and Phaedo, Laws effectively tests the reader’s loyalty to the real Socrates who obeys Athenian law and dies cheerfully in Athens. Having separated Plato from the Stranger, a nuanced defence of Karl Popper’s suspicions about Laws confronts the apologetic readings of both Strauss and Christopher Bobonich. As hinted by his preference for (...) wine, the antidote for hemlock, the Athenian Stranger repeatedly proves himself the opposite of Socrates, particularly with respect to piety. Once the Stranger is recognized as ‘an unreliable narrator’, this apparently ponderous product of Plato’s senility becomes the taut thriller of an innovative teacher at the peak of his powers. (shrink)

Tarán’s case against the authenticity of Epinomis depends on the claim that it is incompatible with Plato’s Laws. Behind this claim is the uncritical assumption that the Athenian Stranger of Laws speaks for Plato. While the Athenian Stranger of Epinomis clearly does not do so, the same is equally true, albeit more difficult to detect, of the Stranger in Laws. Once the Athenian is recognized as both ambitious and impious, a reconstruction of the last sentence of Epinomis — on which (...) Tarán’s incompatibility thesis principally rests — reveals the theological-political continuity between the two dialogues: the Stranger is intent on bringing the city into being while securing divine sanction for his own code of laws and divine honours for himself. Plato appended the Epinomis to the Laws in order to make it easier for the student to recognize the Stranger’s intentions as well as to draw attention to Book VII of the Laws, the centre of the dialogue once Epinomis is recognized as its thirteenth book; it is here that the Stranger describes how a mathematical and astronomical man may become a god to other men. (shrink)

In accordance with Leo Strauss's ingenious suggestion, the Athenian Stranger of Plato's Laws is best understood as an alternative 'Socrates', fleeing from the hemlock to Crete. Situated between Crito and Phaedo, Laws effectively tests the reader's loyalty to the real Socrates who obeys Athenian law and dies cheerfully in Athens. Having separated Plato from the Stranger, a nuanced defence of Karl Popper's suspicions about Laws confronts the apologetic readings of both Strauss and Christopher Bobonich. As hinted by his preference for (...) wine, the antidote for hemlock, the Athenian Stranger repeatedly proves himself the opposite of Socrates, particularly with respect to piety. Once the Stranger is recognized as 'an unreliable narrator', this apparently ponderous product of Plato's senility becomes the taut thriller of an innovative teacher at the peak of his powers. (shrink)

Tarán’s case against the authenticity of Epinomis depends on the claim that it is incompatible with Plato’s Laws. Behind this claim is the uncritical assumption that the Athenian Stranger of Laws speaks for Plato. While the Athenian Stranger of Epinomis clearly does not do so, the same is equally true, albeit more difficult to detect, of the Stranger in Laws. Once the Athenian is recognized as both ambitious and impious, a reconstruction of the last sentence of Epinomis — on which (...) Tarán’s incompatibility thesis principally rests — reveals the theological-political continuity between the two dialogues: the Stranger is intent on bringing the city into being while securing divine sanction for his own code of laws and divine honours for himself. Plato appended the Epinomis to the Laws in order to make it easier for the student to recognize the Stranger’s intentions as well as to draw attention to Book VII of the Laws, the centre of the dialogue once Epinomis is recognized as its thirteenth book; it is here that the Stranger describes how a mathematical and astronomical man may become a god to other men. (shrink)

We report specific heat and μSR measurements on Th and/or B substituted UBe13. The specific heat data show that either Th or B substitution reduces the Kondo temperature TK and increases the entropy at the superconducting transition by almost 20%, indicating an enhanced density of states. However, whereas μSR shows clear evidence for magnetic correlations for Th substitutions, no magnetism is observed for B substitutions. The enhanced specific heat jump in the B-substituted material is associated with a change in the (...) superconducting properties as TK is reduced. (shrink)