Comparing the views of Plato, Aristotle,and Galen on Human DigestionThe unique interpretations ofnatural philosophy given by Plato, Aristotle and Galen offer different perspectives on the human anatomy andphysiology.
The ancient natural philosophers were concerned with the study ofthe structure and function of the human digestive system. Plato, Aristotle,and Galen in their systematic and empirical inquiries make phenomenological anatomicaland physiological observations. Plato’s views of biology are inspired by isimmediate teacher Socrates.
Socrates viewed the humanbody as comprising of the body and the soul (Phaedo 277), teachings that Platoreplicated in his posterior analysis in the humandigestive system. Aristotle adopts the perspective of Plato but introduces theissue of form and matter. In his view, heintegrates subjective description. Galen refined the analysis of the humandigestive system by clarifying on the errors of his predecessors. It is Galen who first brings up the issue ofthe different faculties in living things and integrates the issue of nutrition (Galen, 2017, p.
226). The researchestablishes that the three philosophers offer divergent but complementary views about the interactions inthe human digestive system. Digestion is one of the naturalprocesses whose sole intention and purpose is to ensure that humans survive.The essay will compare the three philosophers chronologically because of thecomplementary nature of their views. First, it is important to look intoPlato’s description of the human digestive system. Plato’s argument was builton Socrates concept of dualism and the separate existence of the human body andthe soul.
The duality as described by Plato is given to humans by the power ofthe gods (Plato 70) As argued humans are created with the sense of necessityplanted within them, it is the necessity that elicits the desire to eat andsensation. Sensation according to Plato created the affections, some of whichare related and particular to the tongue (Plato 100). The affection createscontraction and dilations in addition toother sensations that bring about taste. Plato describes the taste as the reaction of the tongue that isstretched to the heart. In term of its function, he says, “When the musclescontract and dry out and moist the tongue impinges on soft particles of flesh,as they melt down and dry, this creates a ‘sour’ taste (Plato, 2006, p. 100).”For a “tangy” taste the small veins are less rough (Plato, 2006, p. 105).
When the sensation washes of the entire area of the tongue then are names “bitter” while if the parts are lessstrong than bitter then the measure is “salty.” The particles or food moves slip down intothe narrow veins proportionate to Earthly paths (Plato, 2006, p. 105).As he describes there s a separate way for air and for food, food follows thefood path and it slips down the moist hollow channel by being churned along thestretch.Plato argues that the digestivesystem is, “part of the larger circuits that are interconnected in the wholeanimal, as though bound in a prodigious drive(Plato, 2006, p. 74).”In this statement, he views the humandigestive 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 flowsaway (Plato, 2006, p. 74).”He continues with his statement and says that the affections of the human body producean uproar that attacks each other; he describes the action in the digestivesystem as a series of attacks and collisions. For example, he says, “one ofthem could collide with fire, having met something alien from outside or with asolid junk of earth or with liquidgliding of waters (Plato, 2006, p.
74).” Such is the nature of interactions that Platoassociates with the process of digestion inside the human body. Plato describes the functions andthe activities that take place in the liver and the nature of the liver. Heargued that human have a functional liver which indicates the health of the animal (Plato 56). Plato argues that the liver is lucid whenhealth but it turns blind and plain when the human is dead or sick. He notesthat there is an organ next to the liver that assists the liver by keeping itpure and clean. He noted that when impurities are present in the liver then the spleen purifies the impurities andreceives them all (Plato, 2006, p. 108).
Plato describes the spleen as a woven hollow which is usually bloodless.Clearly, Plato defined the liver plays animportant function in the releasing of the sensational digestive juices thataid the process of digestion.Plato further explains that oncethe food is in the tubular cavities it, a motion called “sensing” is activated and it is this activation thatfood moves along the constantly flowing channels to bring about nutriment. Plato also talks of the coiledgrowth of the intestines which plays a major function in the uptake of thenourishment to the soul. Plato takes time to describe that the coiled nature ofthe intestines is structured such that the nourishment cannot pass throughswiftly. In regard to waste food, Plato notes that after nutriment some foodflows contrary to the circuit and as such,it is shaped up into all sorts of contortions at different intervals (Platolecture, slide 31). As noted,incontinence is as a result of gluttony (Timeous, 73A) which causes people touse much more food than required.
These contortions are completely dissolubleand cannot hold up together. As such they havecoursed along, he uses the term, “they are coursed irrationally (Plato, 2006, p. 75).” At this point,Plato describes the end process of digestion in the human body. Immediately after Plato, hisstudent Aristotle offers a personalized view of the human digestive system.Like his predecessor be believed in the dualityof living things but in his perspective living things comprised of form andmatter. His description and view of the digestive system are based on the two concepts. According toAristotle, form describes the shape, purpose and the essence why something wascreated by the gods.
On the other hand, his use of matter was to describe thecomposition of things. Aristotle notes that animals have perception andnutritional potentials and different body parts are suited for different uses (Aristotle, 1997, p. 647). Aristotle looks into the digestive systemsubjectively by describing the different parts of the human digestive system.
The start by identifying the mouth and that is attached to another part calledthe esophagus which is attached to the windpipe. He then looks into the membrane ligatures and the midriffwhich end at the belly. According to Aristotle’s description, the human belly is a flesh-like an organwhich can stretch in all directions. To illustrate the statement he says, “Man’s Stomach resembles that of a dog (Aristotle, 1997, p. 65) .” In this statement, Aristotle notes that the stomach ofhumans is much wider than that of a dog but they are similar in form.
He claimsthat next to the stomach is the gut which is a twisted organ that is somehowwide. Aristotle illustrates that “Thelower stomach of humans is like the pig’s” (Aristotle, 1997, p.69) he notes it is wider and towards the posterior, it is thick and short. As argued byAristotle it is the upper gut and the lower gut that concocts the food with thehelp of natural heat. The stomach gives way to the omentum that he says is attached to the mid stomach and is made upof fatty membranes. The omentum ispresent in all omnivores. The gut is interconnected to the mesentery which as describedby Aristotle is a membranous fatty organ with a network of blood vessels thatabsorb nutrition. He notes that “the body will take up the nutrients fromthe stomach and the intestines as from a trough (Aristotle, 1997, p.
24).”He notes that blood is the last part of nutrition and it becomes nourished bytaking up a concoction of a rich diet. Aristotle just like Platoacknowledged the structure and function of the liver and its location andrelationship with the spleen. Whereas Plato, described the position of the liverto be adjacent to the stomach, Aristotle described the liver to be below the diaphragmon the right and the spleen was adjacent to the left side (Aristotle, 1997, p.
69).It is clear that both Plato and Aristotle noted that the two organs weretransposed and they did similar functions. They also agreed that the two werelinked to the stomach. However, in terms of description,Aristotle describes the form of the human liver to be similar to that of thepig (Aristotle, 1997, p. 69).
He goes ahead to claim that most organisms lack a gallbladder although it ispresent in some few animals. On the other hand, Aristotle describes the liverof a man as round in shape and it resembles that of an ox. Finally, heacknowledges that the liver just like any other organ is interconnected to agreat 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 ofteleology. Although the cam much later he pioneered and madesignificant contributions towards the understanding of the human digestivesystem (Galen, 2017, p. 221).
Galen’s perspective is more refined as he notes that the human nutritionfaculties comprise of four majorprocesses namely, Attractive process, retentive process, alternative and propulsive faculties (Galen,2017, p223) Galen brings a new approach towards the process of digestion byintroducing a process. The attractiveprocess is the process by which organs exert attachment and attraction tospecific products and materials, forexample, 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 forthe animals benefit (Galen, 2017, p. 225).”The statement means that nature has natural ways of making animals to beattracted to nourishment. The retention process is anotherfaculty that Galen mentions, this faculty is attached to the stomach.
Like his predecessors, Galen looks at the stomach notfrom a structural perspective but from a functional perspective. Galen says the parts of an animal that ate especiallyhollow for a reason are the stomach and the organ called the uterus. He notedthat the retention faculty is usually managed by the senses whilst other partsof the body. He notes that “for the stomach, it retains food until it has beenfully digested (Galen, 2017, p.
229),”here Galen is giving the function of the stomach. Galen further reinforces his retentionprocess through the use of dissection, heargues that if one fills any animals with any food like I have carried out withpigs then cuts it open after three or four hours then it is likely that you canfind the food in the stomach. Practically, using dissection Galen is able tooffer proof about the function of the stomach in retention of food. Thefunctional perspective adopted by Galen is different from the descriptiveapproach employed by Plato and Aristotle. Retention of food in the stomachinitiates a third process which Galen calls alteration, which is the process bywhich the stomach and the liver will alter and subdue the food. Alteration of the food changes the substanceof the food into nutriment substance for the blood (Galen, 2017, p.
248). The stomach follows through thedigestion to make the food suitable for other organs. Each of the organs in the body draws nutrimentalongside it and devours the useful fluids until the organism is satisfied. Ifsatisfied the excess nutriment is storedup for assimilation. The process is different from what happens in the mouthwhere the food is transformed into a new form but it is not completely altered fornourishment. After nourishment, the foodis saturated with fluid and other food and becomes a burden and thus thestomach has to get rid of the excess. As reported, the excess food is turneddownwards passing through the length of the intestine and becomes presented forpropulsion.
In summary, the views of Plato, Aristotle, and Galen on the structure andfunction of the human digestive system are divergent but complimentary. The complementarynature of the views is evident when analyzing the scope and the influence ofthe philosophers on one another. Plato offers a conceptual framework for the process of digestion inhumans. Then Aristotle gives the order names of the organs involved in theprocess of digestion. Galen compliments both Plato and Aristotle by describingthe entire human digestion process accurately.
Divergent views come from theirdifferent approaches towards understanding the nature and teleologicalrelationship. The three have different beliefs and it is their beliefs whichinfluenced their descriptions.