John H. Campbell

On a classical conception, knowing the sense of a proposition is knowing its truth-condition, rather than simply knowing how to verify the proposition, or how to find its implications (whether deductive implications or implications for action). But knowing the truth-condition of a proposition is not unrelated to your use of particular methods for verifying the proposition, or finding its implications. Rather, your knowledge of the truth-condition of the proposition has to justify the use of particular methods for verifying it, or finding its implications. And your knowledge of the truth-condition of the proposition has to be what causes your use of particular methods for verifying it or finding its implications. So on a classical picture, we do not appeal to knowledge of sense only in explaining the informativeness of identities. We have to think of knowledge of sense as what causes, and justifies, your use of particular ways of verifying or finding the implications of a proposition. I argue that in the case of a perceptual demonstrative, like 'that star' or 'that mountain', it is conscious attention to the object that causes, and justifies, your use of particular ways of verifying or finding the implications of propositions involving the demonstrative. So conscious attention to the object is what constitutes your grasp of the sense of the demonstrative. This runs counter to the philosophical tradition since Locke, which takes it that the role of experience in understanding has to do solely with the verification of propositions. I argue that once we think of conscious attention as a pre-intentional acquaintance with the object itself, we can see how it is possible to think of understanding as consisting in knowledge of classical truth-conditions

"A blab droid is a robot with a body shaped like a pizza box, a pair of treads, and a smiley face. Guided by an onboard video camera, it roams hotel lobbies and conference centers, asking questions in the voice of a seven-year-old. "Can you help me?" "What is the worst thing you've ever done?" "Who in the world do you love most?" People pour their hearts out in response. This droid prompts the question of what we can hope from social robots. Might they provide humanlike friendship? Philosopher John Campbell doesn't think so. He argues that, while a social robot can remember the details of a person's history better than some spouses can, it cannot empathize with the human mind, because it lacks the faculty for thinking in terms of singular causation. Causation in Psychology makes the case that singular causation is essential and unique to the human species. From the point of view of practical action, knowledge of what generally causes what is often all one needs. But humans are capable of more. We have a capacity to imagine singular causation. Unlike robots and nonhuman animals, we don't have to rely on axioms about pain to know how ongoing suffering is affecting someone's ability to make decisions, for example, and this knowledge is not a derivative of general rules. The capacity to imagine singular causation, Campbell contends, is a core element of human freedom and of the ability to empathize with human thoughts and feelings"--

It is sometimes said that ordinary linguistic exchange, in ordinary conversation, is a matter of securing and sustaining joint attention. The minimal condition for the success of the conversation is that the participants should be attending to the same things. So the psychologist Michael Tomasello writes, ‘I take it as axiomatic that when humans use language to communicate referentially they are attempting to manipulate the attention of another person or persons.’ I think that this is an extremely fertile approach to philosophical problems about meaning and reference, and in this paper I want to apply it to the case of the first person. So I want to look at the case in which you tell me something about yourself, using the first person, and we achieve joint attention to the same object. But I begin with some remarks about how this approach applies to proper names and to perceptual demonstratives

It is sometimes said that ordinary linguistic exchange, in ordinary conversation, is a matter of securing and sustaining joint attention. The minimal condition for the success of the conversation is that the participants should be attending to the same things. So the psychologist Michael Tomasello writes, ‘I take it as axiomatic that when humans use language to communicate referentially they are attempting to manipulate the attention of another person or persons.’ I think that this is an extremely fertile approach to philosophical problems about meaning and reference, and in this paper I want to apply it to the case of the first person. So I want to look at the case in which you tell me something about yourself, using the first person, and we achieve joint attention to the same object. But I begin with some remarks about how this approach applies to proper names and to perceptual demonstratives.

We can make a distinction between the conceptual role of the first person and the reference of the first person. By ‘conceptual role’ I mean the use that is made of the term: the kinds of procedures that we use in verifying judgements using the term and the kinds of actions we perform on the basis of judgements involving the term. In “Self-Notions,” Perry talks about conceptual role using the phrase, ‘epistemic/pragmatic relations’. He says there are “normally self-informative” ways of getting information and “normally self-dependent” ways of acting. These ways of getting information about the self, and ways of acting dependent on the self, constitute what I am calling the conceptual role of the first person. Perry indeed says, “I believe that what is special about self-notions is that they are the normal repository of normally self-informative ways of perceiving, and the normal motivator of normally self-dependent ways of acting.”

Ever since the publication of 'Truth' in 1959 Sir Michael Dummett has been acknowledged as one of the most profoundly creative and influential of contemporary philosophers. His contributions to the philosophy of thought and language, logic, the philosophy of mathematics, and metaphysics have set the terms of some of most fruitful discussions in philosophy. His work on Frege stands unparalleled, both as landmark in the history of philosophy and as a deep reflection on the defining commitments of the analytic school. This volume of specially composed essays on Dummett's philosophy presents a new perspective on his achievements, and provides a focus for further research fully informed by the Dummett's most recent publications. Collectively the essays in philosophy of mathematics provide the most sustained discussion to date of the role of Dummett's diagnosis of the root of the logico-mathematical paradoxes in his case for an intuitionist revision of classical mathematics. The themes of other essays include a fundamental challenge to Dummett's Fregean understanding of predication, and a criticism of his case for logical revision outside of mathematics.

The objective of this study was to compare nutrient concentration, distribution, and select components of nutrient budgets for aspen, jack pine, and black spruce forest ecosystems at the BOReal Ecosystem Atmosphere Study, southern and northern study areas near Candle Lake, Saskatchewan and Thompson, Manitoba, Canada, respectively. The vegetation in the aspen, black spruce, and jack pine stands contained 70-79%, 53-54%, and 58-67% of total ecosystem carbon content, respectively. Soil nitrogen, calcium, and magnesium content comprised over 90% of the total ecosystem nutrient content, except for Ca and Mg content of the southern black spruce stand and Ca content of the southern aspen stand which were less than 90%. Annual litterfall N content was significantly greater for trembling aspen than for jack pine or black spruce, and was generally greater, but not significantly, for the southern than for the northern study area. Aboveground net primary production was positively correlated to annual litterfall N content for the BOREAS forests, and for all boreal forests. Annual aboveground nutrient requirements were significantly greater for trembling aspen than for jack pine or black spruce forests. Annual aboveground N requirements ranged from 37-53, 6-14, and 6-7 kg N ha-1 yr-1 for trembling aspen, jack pine, and black spruce forests, respectively. The greater nutrient requirements of deciduous than evergreen boreal forests was explained by a greater annual production of biomass and lower use efficiency of nutrients. Nutrient cycling characteristics of boreal forests were influenced by climate and forest type, with the latter having a greater influence on litterfall N, annual nutrient requirements, nutrient mean residence time, and nutrient distribution.