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On Probabilities and Confirmation Holism

According to a theory of knowledge called confirmation holism, we believe facts on the basis of their being part of a larger body of knowledge that we believe in total. For example, my belief in Sweden is a part of my knowledge of geography and history as a whole. I would have to doubt much of what I know of the nations and history of the world to disbelieve in Sweden. One problem that's been advanced against such confirmation holism is the idea that we must have to assign each fact we know a probability, and then, by the laws of probability, don't we calculate the odds of our entirety of holistic conjunction of facts just as the product of the individual probabilities? For example, if we believe each fact of a 500-fact conjunction with p = 0.95, does this make our degree of belief in the 500-conjunct equal to (0.95)^500, or just 0.0000000000073? But, of course, we DON'T calculate the probabilities of the whole this way! The multiplication rule for the conjunct of two p…
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Is the Human Body a Ship of Theseus? Comments on an Urban Legend in Identity

The Ship of Theseus is a classic thought experiment in Greek philosophy. As related by Plutarch the historian, Theseus' ship was kept as a famous artifact, and, over the years, as its wood decomposed the boards were replaced, until none of that ship was the same wood as the original. Was that ship still the ship of Theseus after all those replacements? Heraclitus, who said all was change, would likely have said not the same ship, and Plato and Aristotle, with their emphasis on form as what makes things what they are, might have thought otherwise. In a materialistic society, there are direct implications of the story for questions of identity over time--including human identity. In The God Delusion, Richard Dawkins quotes, with apparent approval:
Steve Grand points out that you and I are more like waves than permanent 'things'. He invites his reader to think . . . ... of an experience from your childhood. Something you remember clearly, something you can see, feel, …

Gilles Deleuze on why the individual is not the species.

For Deleuze, perhaps to exist was not just to make a difference: it was to be a difference, to be uniquely configured by the effects of the singular flows within the configuration spaces by which a thing becomes what it individually is. One wonders what exactly Deleuze would now point to as the Source of difference in what exists? The vagueness of species is predicated on the difference of the individual. Beneath the general operation of laws, however, there always remains the play of singularities. Cyclical generalities in nature are the masks of a singularity which appears through their interferences; and beneath the generalities of habit in moral life we rediscover singular processes of learning. The domain of laws must be understood, but always on the basis of a Nature and a Spirit superior to their own laws, which weave their repetitions in the depths of the earth and of the heart, where laws do not yet exist. The interior of repetition is always affected by an order of differe…

Too much of a good thing? Autism and Cortical Architecture

Brain microscopic anatomy in persons with autism shows an increase in the numbers of neuronal "dentritic spines" whuch conect neighboring cells in the brain. The dendritic spine density of the apical dendrites of pyramidal neurons are increased in several cortical layers (cortical layer 2 in frontal and parietal lobes and layers 2 and 5 in the temporal lobes). Spine density seems inversely correlated with cognitive function. Neurologists have hypothesized that the autism patient's brain is locally overconnected, so that the good connections are crowded out by poorly pruned, inefficient ones. Something along those lines seems to fit the report below. Perhaps even in the first year of life, the brains of those who are to more obviously develop autism in the second year of life grow in a way that causes an unusual increase in cortical surface area. That means that their outer brain cortex is actually expanding faster than that of normal infants. Unfortunately, not all suc…

This is your Brain on E-Cigarettes

From the bioRxiv.org preprint site, some evidence that e-smoking is potentially habit-forming. Like ordinary smoking as well as several other habit forming drugs, e-cigarette smoking causes increased posterior striatal metabolism, which often correlates with addictive craving and behavior. ------------------------------------------------------------------------ ABSTRACT The effect of smoking on the brain revealed by using electronic cigarettes with concurrent fMRI Matthew B Wall, Alexander Mentink, Georgina Lyons, Oliwia S Kowalczyk, Lysia Demetriou, Rexford D Newbould doi: https://doi.org/10.1101/107771 Cigarette addiction is driven partly by the physiological effects of nicotine, but also by the distinctive sensory and behavioural aspects of smoking, and understanding the neural effects of such processes is vital. There are many practical difficulties associated with subjects smoking in the modern neuroscientific laboratory environment, however electronic cigarettes obviate m…

Earlier Noncontact Exercise May Decrease Risk of PostConcussive Syndrome in Youth

The best practice estimates regarding the timing of return to high levels of physical activity in sports after concussion keeps changing in recent years. The study below suggests that early return to exercise type, non-contact sports practice may be beneficial after concussion. The best protocol then might be early reintegration into non-contact practice but only later restart of physical contact practice and games after concussion in sports, at least at the junior high and high school levels, contingent at least until further study is done. ABSTRACT =========================================================== Association Between Early Participation in Physical Activity Following Acute Concussion and Persistent Postconcussive Symptoms in Children and Adolescents Anne M. Grool, MD, PhD1; Mary Aglipay, MSc1; Franco Momoli, PhD1; et al William P. Meehan III, MD2; Stephen B. Freedman, MDCM, MSc3; Keith Owen Yeates, PhD4; Jocelyn Gravel, MD5; Isabelle Gagnon, PhD6; Kathy Boutis, MD7; …

Split Brain Research Fails to Replicate Different Hemisphere Awareness After Corpus Callosotomy

According to the Nobel-prize-winning work in the 1960's by Sperry and Gazzaniga, after the two cerebral hemisphere are cut by callosotomy (a surgery sometimes done for intractable epilepsy), a person seeing an object in one visual field can signal seeing it with the hand on that side, but not with the hand on the other side, which will respond as if no object was seen. I'd heard several tales in more recent years from neuropsychologists just out of university training of how researchers at their institutions were failing to replicate those classic results. This was usually attributed to variations in the surgery performed, as well as the fact the posterior commissure was usually left intact. However, in a recent issue of Brain,Pinto and colleagues below report they have systematically re-studied many of the patients from these surgeries and are showing that a single awareness persists in such subjects-- exactly as the persons who had the surgery (I've seen three since …