Category: Uncategorized
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Evolution: Tinkerer and economizer
Cajal is very much an evolutionary thinker, but he also definitely sees the evolving nervous system as working toward something, in vaguely cosmic or spiritual terms. (The word ‘perfect’ appears 86 times in Vol I of the Textura… the word ‘brain’ appears 57 times). He considers, for example, the mammalian brain to be “the ultimate…
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Psychomotor cells
Cajal gives us a few words about a very special type of motorneuron, which he refers to as “psychomotor.” He clearly sees this as the nervous system’s secret sauce. “Its mission is to take the commands of the will to all neural foci […]. Memory, will, and intelligence emerge with it.” It’s not that the…
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Worms and Jellyfish
Like James, Cajal is a master expositor of scientific ideas. He grounds us in “didactic” examples of relatively simple nervous to illustrate basic principles, and then builds on these through successive approximations, gradually climbing the phylogenetic ladder. Today it’s not really fashionable (or correct) to talk about ‘lesser’ and ‘lower’ forms, but as a pedagogical…
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The Textura
So, we’re setting aside James for a bit, and moving on to the first chapter of Cajal’s Textura. Whereas James is an explorer of inner life in the sense of that which is available to introspection, Cajal explores the inner, skull-bound world which is visible with a microscope. He wants to understand how neurons (brain…
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Blood and phosphorus
This is a little bit of an oddball section where James talks about cerebral blood supply, and where he weighs in on the issue of the unique role of phosphorous in thought (evidently this was contended strongly enough in his time that it gets a special mention here). We have such an inflated and mystical…
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On reaction times
Yeah, I know. I’ll confess I find it pretty hard to get pumped about studying reaction times. It seems James is a kindred spirit here, noting that the literature on it is the “sort of work which appeals particularly to patient and exact minds.” But since reaction time is one of the few toeholds he…
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Brain activity and thought
(So, I lied when I said in my original blog post that we’d trade off between James and Cajal a chapter at a time. I’m going to move on to chapter 3 of The Principles because in many ways it’s a continuation of the previous one. I suspect that for the presently –well– ‘lean’ readership…
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James as a father
Something a little lighter. A lovely letter from James to his 8 year old daughter Margaret (“Peg”), written in 1895. You can see how large-hearted he is. He really makes an effort to share his world. “Sweetest of Living Pegs, —Your letter made glad my heart the day before yesterday, and I marveled to see what…
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Summary/cheatsheet for chapters 1 & 2
(A recap of some big picture ideas from Chapters 1 and 2. I’m summarizing pretty densely here, and for my own later reference, but if you’ve read the posts up to here this should all be sensible). I. James’ project is strongly rooted in ideas about evolution and natural history. He’s very interested in the…
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Final thoughts on the Meynert scheme. We’re (probably) not just bundles of reflexes.
James wraps up his chapter on the brain by offering his final “correction” of the Meynert scheme, and these corrections are important for his later considerations on the role of the will, instincts, and emotions in behavior. I don’t know what the intellectual climate was at the time, but it seems like Meynert’s ideas (which…
The Excitable Membrane 