No thought without phosphorus
In quotes, no thought without phosphorus (LH:3) is a debated motto, championed by Jacob Moleschott (c.1849), and promoted by Ludwig Buchner (1855), which summarized studies and research from the previous 150-years, which attempted to correlated the element phosphorus, fat in fish, the brain, and thought.
In 1669, Hennig Bradt isolated phosphorus as a free element.
In 1719, Johann Hensing igniting cattle brains, and had determined from the flames that brains were comprised of phosphorus. Specifically, he heated cattle brains with alum (aluminum potassium sulfate) in the absence of air for several hours. When he introduced air to the residue it caught fire spontaneously and from this he deduced that phosphorus was present.
In 1811, Nicholas Vauquelin was reporting the following experimental findings:
- “There is phosphorus combined in the fatty matter of the brain and which dissolved in alcohol at the same time as the fatty matter... (The substance) has more analogy with tallow and fat than any other class of bodies, yet it ought not be confounded with ordinary fat. Thus, though we class it among fatty bodies, we ought to consider it as a particular and new species.”
- — Nicolas Vauquelin (1811), Publication
Vauquelin's reported data for the mass composition of human brains, are tabulated adjacent.
In 1834, Jean Couerbe did brain composition experiments, finding that the brain was 1.0 to 4.5% phosphorus in mass; and also reported the following:
- Idiots: 1.0-1.5 percent
- Normal brains: 2.0-2.5 percent
- Madman: 3.0-4.5 percent
The average amount of phosphorus in the total body (see: elemental composition of a human) is 1.1%. Hence, higher amounts of phosphorus are found in the brain, compared to the body.
In c.1847, Louis Agassiz (1807-1873), knowing that fish is rich in phosphorus and that eating fish is good for the brain, conjectured that phosphorus is essential for brain activity.
Feuerbach | Moleschott
In late 1840s, Feuerbach was lecturing
- “One is what one eats. Is it any wonder that it is so dark in the world because our greatest thinkers had no phosphorus in their heads... and, in connection with the unsuccessful German revolution of 1848 ... food becomes blood, blood becomes heart and brain, thoughts and thinking stuff. Whoever restricts himself to vegetables is only a vegetative being, without any vigor.”
- — Ludwig Feuerbach (c.1848), Publication
- “The brain cannot exist without phosphorus-containing fat. The phosphorus is the origin, hence also established activity of the brain — without phosphorus no thought.”
Liebig laughed at the idea stating that, if this were so, bones would be the greatest philosophers in the worlds:
- “If phosphorus were the substance of thought, then bones would be the greatest philosophers.”
- — Justus Liebig (c.1851), Publication
This ‘phosphorus = mind’ motto, in the half-century to follow, became popular.
Overton | Lipid bilayer
In 1889, Charles Overton, published a work, based on a series of studies to determine which molecules were able to cross this cell boundary layer, the then prevalent view being that only water could cross the boundary, which showed that nonpolar chemicals were usually able to cross the boundary quite easily. Overton explicitly suggested that the boundary layer was a lipid and that other lipids were able to freely enter and pass through.
In 1990s, it was realized that an omega-3 fatty acid in fish, called docosahexaenoic acid (DHA), chemical formula: C22H32O2, one of the dominate parts of the gray matter of the brain, is what is mostly responsible for heightened brain function, specifically in respect to memory, related to fish consumption:
Note also that while DHA is associated with higher IQ and better memory, that oleic acid, which forms the main structural component of the "white matter" portion of the brain, making up the myelin sheath shown above, is also important for speed of thought.
In sum, phosphorus the 6th most abundant element in the composition of humans, making up 1.1% of the mass of a person. It is in the phospholipid bilayers of ever cell, and is in energy molecules, such as ATP. The brain needs a certain amount of phosphorus to function.
Generally speaking, however, we know that in terms of the patterns of the periodic table, the Thims periodic table shown below, that column 14 elements tend to be "mind-property" related, and that column-15 elements, where phosphorus is found, tend to be "power-property" types of elements: 
The element boxes shown with "thickened borders" (elements in humans) as compared to thin borders (elements not in humans) signify the 26 elements in human composition; some of which are shown with modification, e.g. dotted lines (CHNOPS elements) or white inside border (extra four Thims elements), as explained below.
We note that too much phosphorus, turns the brain mad, and too little turns the mind towards idiocy and low levels are found in Alzheimer's patients. The word seems to be still out on the nature of phosphorus and thought?
In 2009, Alan Dronsfield and Pete Ellis, in their “Phosphorus: Food for Thought”, give a good short history of the "phosphorus and mind" discussion.
The following are quotes:
- “Agassiz does recommend authors to eat fish, because the phosphorus in it makes brains. But I cannot help you to a decision about the amount you need to eat. Perhaps a couple of whales would be enough.”
- “A German physiologist [Moleschott, c.1849] has said that there is ‘no thought without phosphorus’. He might as well have said that there is no thought without carbon, no thought without oxygen, without nitrogen, or without any one of the numerous elements which enter into the molecular constitution of the nervous system. There is no mental condition—no thought, and no feeling—which is not the mental shadow, or equivalent, or obverse, or accompaniment, of some process, some discharge, some disturbance of tension, or some molecular rearrangement in the nervous centers. This is the secret of the connection between body and mind.”
- — Charles Mercier (1895), Sanity and Insanity (pg. 52)
- Dronsfield, Alan; Ellis, Pete. (2009). “Phosphorus: Food for Thought” (WB), Education in Chemistry, RSC.org, Oct 31.
- Ward, Philip; Edwards, Julia. (2013). The book of Common Fallacies (pg. 157). Skyhorse.
- Smith, Douglas B. (2013). Every Wonder Why? (pg. #). Random House.
- (a) Feuerbach, Ludwig. (1850). “The Natural Sciences and the Revolution” (“Die Naturwissenschaft und die Revolution”) (German → English). Publisher.
(b) Feuerbach, Ludwig. (1975). Feuerbach’s Works, Volumes 1-6 (editor: Thies) (vol. 4, pgs. 243-65; quote, pgs. 253-54). Frankfurt.
- Meneghello, Laura. (2017). Jacob Moleschott - A Transnational Biography: Science, Politics, and Popularization in Nineteenth-Century Europe (pg. 134). Verlag.
- Adams, Mike. (2010). “Discovering: the Lipid Bilayer”, Nature Education, 3(90):20.
- Thims, Libb. (2020). Human Chemical Thermodynamics (§1.3:Periodic Table, pgs. 6-8)) (pdf). Publisher.