Considering Plato's, Aristotle's, and Galen's perspectives on human digestion

Natural philosophy eisegesis and Plato's, Aristotle's, and Galen's explanations offer distinct viewpoints on human anatomy and physiology. Ancient natural philosophers were fascinated by the structure and function of the human digestive system. Plato, Aristotle, and Galen make phenomenological, anatomical, and physiological observations in their systematic and empirical investigations. Socrates, Plato's personal tutor, influenced his views on biology. Socrates taught that the human body was made up of the body and the soul, which Plato duplicated in his later research of the human digestive system. Aristotle embraces Plato's viewpoint but adds the issue of form and matter. In his view, he integrates subjective description. Galen refined the analysis of the human digestive system by clarifying on the errors of his predecessors. It is Galen who first brings up the issue of the different faculties in living things and integrates the issue of nutrition . The research establishes that the three philosophers offer divergent but complementary views about the interactions in the human digestive system.

The converging point is that humans are immortal and their very existence can be attributed to the teleological desire of the goods. The natural world contains designed and discernible natural processes . Digestion is one of such natural processes whose intention and purpose is to ensure that humans survive. The essay will compare the three philosophers chronologically because of the complementary nature of their views. First, it is important to look into Plato’s description of the human digestive system . Plato’s argument was built on Socrates concept of dualism and the separate existence of the human body and the soul. The duality as described by Plato is given to humans by the power of the gods . As argued humans are created with the sense of necessity planted within them, it is the necessity that elicits the desire to eat and sensation. Sensation according to Plato created the affections, some of which are related and particular to the tongue . The affection creates contraction and dilations in addition to other sensations that bring about taste. Plato describes the taste as the reaction of the tongue that is stretched to the heart. In term of its function, he says, “When the muscles contract and dry out and moist the tongue impinges on soft particles of flesh, as they melt down and dry, this creates a ‘sour’ taste .” For a “tangy” taste the small veins are less rough . When the sensation washes of the entire area of the tongue then are names “bitter” while if the parts are less strong than bitter then the measure is “salty.” The particles or food moves slip down into the narrow veins proportionate to Earthly paths . As he describes there s a separate way for air and for food, food follows the food path and it slips down the moist hollow channel by being churned along the stretch.

Plato argues that the digestive system is, “part of the larger circuits that are interconnected in the whole animal, as though bound in a prodigious drive .” In this statement, he views the human digestive system as a circuitry of interconnected tubes. Like a river, Plato views the digestive system as a river designed in such a way that “food-supplying wave washes over it and then flows away .” He continues with his statement and says that the affections of the human body produce an uproar that attacks each other; he describes the action in the digestive system as a series of attacks and collisions. For example, he says, “one of them could collide with fire, having met something alien from outside or with a solid junk of earth or with liquid gliding of waters .” Such is the nature of interactions that Plato associates with the process of digestion inside the human body.

Plato describes the functions and the activities that take place in the liver and the nature of the liver. He argued that human have a functional liver which indicates the health of the animal . Plato argues that the liver is lucid when health but it turns blind and plain when the human is dead or sick. He notes that there is an organ next to the liver that assists the liver by keeping it pure and clean. He noted that when impurities are present in the liver then the spleen purifies the impurities and receives them all . Plato describes the spleen as a woven hollow which is usually bloodless. Clearly, Plato defined the liver plays an important function in the releasing of the sensational digestive juices that aid the process of digestion.

Plato further explains that once the food is in the tubular cavities it elicits greatest commotions . He says that it is under these commotions that motions called “sensing’s” is activated and it is this activation that food moves along the constantly flowing channels to bring about nutriment and this severely shakes the circuits of the human soul . Plato talks of the coiled growth of the intestines which plays a major function in the uptake of the nourishment to the soul. Plato takes time to describe that the coiled nature of the intestines is structured such that the nourishment cannot pass through swiftly. In regard to waste food, Plato notes that after nutriment some food flows contrary to the circuit and as such, it is shaped up into all sorts of contortions at different intervals . As noted, incontinence is as a result of gluttony which causes people to use much more food than required. These contortions are completely dissoluble and cannot hold up together. As such they have coursed along, he uses the term, “they are coursed irrationally .” At this point, Plato describes the end process of digestion in the human body.

Immediately after Plato, his student Aristotle offers a personalized view of the human digestive system. Like his predecessor be believed in the duality of living things but in his perspective living things comprised of form and matter. His description and view of the digestive system are based on the two concepts. According to Aristotle, form describes the shape, purpose and the essence why something was created by the gods. On the other hand, his use of matter was to describe the composition of things. Aristotle notes that animals have perception and nutritional potentials and different body parts are suited for different uses . Aristotle looks into the digestive system subjectively by describing the different parts of the human digestive system. The start by identifying the mouth and that is attached to another part called the esophagus which is attached to the windpipe. He then looks into the membrane ligatures and the midriff which end at the belly.

According to Aristotle’s description, the human belly is a flesh-like an organ which can stretch in all directions. To illustrate the statement he says, “Man’s Stomach resembles that of a dog .” in this statement, Aristotle notes that the stomach of humans is much wider than that of a dog but they are similar in form. He claims that next to the stomach is the gut which is a twisted organ that is somehow wide. Aristotle illustrates that “The lower stomach of humans is like the pig’s” he notes it is wider and towards the posterior, it is thick and short. As argued by Aristotle it is the upper gut and the lower gut that concocts the food with the help of natural heat . The stomach gives way to the omentum that he says is attached to the mid stomach and is made up of fatty membranes. The omentum is present in all omnivores. The gut is interconnected to the mesentery which as described by Aristotle is a membranous fatty organ with a network of blood vessels that absorb nutrition. He notes that “the body will take up the nutrients from the stomach and the intestines as from a trough.” He notes that blood is the last part of nutrition and it becomes nourished by taking up a concoction of a rich diet.

Aristotle just like Plato acknowledged the structure and function of the liver and its location and relationship with the spleen. Whereas Plato, described the position of the liver to be adjacent to the stomach, Aristotle described the liver to be below the diaphragm on the right and the spleen was adjacent to the left side . It is clear that both Plato and Aristotle noted that the two organs were transposed and they did similar functions. They also agreed that the two were linked to the stomach. However, in terms of description, Aristotle describes the form of the human liver to be similar to that of the pig . He goes ahead to claim that most organisms lack a gallbladder although it is present in some few animals. On the other hand, Aristotle describes the liver of a man as round in shape and it resembles that of an ox. Finally, he acknowledges that the liver just like any other organ is interconnected to a great blood vessel.

Galen, on the other hand, shares a lot of basic beliefs with Plato and Aristotle. He specifically believed in the Plutonic tri-partite soul and the Aristotelian belief in dissection and the impact of teleology. Although the cam much later he pioneered and made significant contributions towards the understanding of the human digestive system . Galen’s perspective is more refined as he notes that the human nutrition faculties comprise of four major processes namely, Attractive process, retentive process, alternative and propulsive faculties (Washburn 50). Galen brings a new approach towards the process of digestion by introducing a process. The attractive process is the process by which organs exert attachment and attraction to specific products and materials, for example, food is attractive to the eyes and it initiates the desire to feed or appetite. As indicated by Galen, “nature is solicitous and this is purposely for the animals benefit .” The statement means that nature has natural ways of making animals to be attracted to nourishment.

The retention process is another faculty that Galen mentions, this faculty is attached to the stomach. Like his predecessors, Galen looks at the stomach not from a structural perspective but from a functional perspective . Galen says the parts of an animal that ate especially hollow for a reason are the stomach and the organ called the uterus. He noted that the retention faculty is usually managed by the senses whilst other parts of the body. He notes that “for the stomach, it retains food until it has been fully digested ” here Galen is giving the function of the stomach. Galen further reinforces his retention process through the use of dissection, he argues that if one fills any animals with any food like I have carried out with pigs then cuts it open after three or four hours then it is likely that you can find the food in the stomach. Practically, using dissection Galen is able to offer proof about the function of the stomach in retention of food. The functional perspective adopted by Galen is different from the descriptive approach employed by Plato and Aristotle.

Retention of food in the stomach initiates a third process which Galen calls alteration, which is the process by which the stomach and the liver will alter and subdue the food. Alteration of the food changes the substance of the food into nutriment substance for the blood . The stomach follows through the digestion to make the food suitable for other organs. Each of the organs in the body draws nutriment alongside it and devours the useful fluids until the organism is satisfied . If satisfied the excess nutriment is stored up for assimilation. The process is different from what happens in the mouth where the food is transformed into a new form but it is not completely altered for nourishment. After nourishment, the food is saturated with fluid and other food and becomes a burden and thus the stomach has to get rid of the excess. As reported, the excess food is turned downwards passing through the length of the intestine and becomes presented for propulsion.

In summary, the views of Plato, Aristotle, and Galen on the structure and function of the human digestive system are divergent but complimentary. The complementary nature of the views is evident when analyzing the scope and the influence of the philosophers on one another. Plato offers a conceptual framework for the process of digestion in humans. Then Aristotle gives the order names of the organs involved in the process of digestion. Galen compliments both Plato and Aristotle by describing the entire human digestion process accurately. Divergent views come from their different approaches towards understanding the nature and teleological relationship. The three have different beliefs and it is their beliefs which influenced their descriptions.

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