We can trust our senses when we are gathering sensory inputs for data observation to obtain the subjective sense of the truth. Subjective truth is “a personal or relative truth which is tied to the individual and more embodied.” (Hoffman) Due to certain alterations made by external means or circumstances, our sense perception provides us with “different truths” based on personal experiences. What is perceived through sense is very personal to an individual, and is subjective in a individualistic way. How one interprets and organizes sensory information might not be the same as the others, due to various past experiences and different object relations to certain sensory information. The subjectivity of the senses is shown also in an area of knowledge, arts. A famous example would be John Cage’s composition, 4’33, which he calls “a piece of uninterrupted silence” (Cage) - a three-movement composition for any instrument, which instructs the performer not to play during the entire duration. For an audience which appreciates aesthetic value, the composition consists entirely of silence, and it is hard for them to classify this composition as music. However, those who understand artistic conceptual value may appreciate the concept of which this composition was based on; the idea that silence is in fact an abstract notion, (Cage 81) and also to allow audiences a time to heighten their auditory perception to take note of the common sounds they are exposed to everyday. In terms of senses, everyone hears the same thing, within the same setting. However, after interpreting the piece differently in terms of conceptual or aesthetic value after bringing in other ways of knowledge, emotion and reason, leading to divergent opinions which are both undeniably true to each person. Senses in this case has succeeded in providing subjective truth, truth which is not uniform amongst people but invariable within individuals.
However, occasions when sensory perceptions contradict a knower’s expectations exist due to the unreliability of our senses. In the First Meditation of his Meditations on First Philosophy, Descartes writes:“Whatever I have up till now accepted as most true I have acquired either from the senses or through the senses. I observed, however, that these sometimes misled us; and it is the part of prudence not to place absolute confidence in that by which we have even once been deceived.” (Descartes) Not placing absolute confidence in our senses does not mean questioning every single proposition derived from sensory perception, but instead considering them carefully. When a contradictory proposition is exposed to a knower, an intuitive response would be to critically evaluate this using his past experiences and knowledge. For example, the case of spatial disorientation, "A state characterized by an erroneous sense of one's position and motion relative to the plane of the earth's surface” (Shaw) whereby pilots are unable to accurately interpret aircraft altitude, altitude or airspeed in relation to the Earth, having to completely disregard sensory information and place full confidence on reference instruments. Our sense of balance is regulated by our inner ear’s fluid, and pilots are often exposed to 10 to 20 seconds of constant angular acceleration while flying, rendering the sensation of motion transmitted to the brain false. (Shaw) Fixed acceleration threshold, whereby the pilot cannot sense any rotation at all, is also evident. Such falsity encouraged by the senses may endanger pilot’s lives and therefore they must refer to the reference instrument at all times to ensure their senses are not misleading them. Senses in this case, cannot be fully reliable, and senses do deceive by not giving us real truth.
Truth is limited by the extent which our senses can perceive it, and we as humans are limited in grasping true reality based on the limitations of our flesh. The nature of our sense organs do not allow us to fully perceive our environment in its entirety. While our 5 senses give us valuable information about the environment, they each have a limited range of sensitivity and capture only certain kinds of data within their scope of ability. For example, our auditory ability does not allow us to comprehend sounds that are of a frequency higher than 2000 Hz due to the full human auditory range of 20 to 2000 Hz , compared to bats, whose auditory abilities allow them to hear sounds that are between 20Hz to 150000 Hz (SPI), therefore enabling them to use echolocation to navigate and forage in total darkness. While we do share the same senses with these animals, they are able to attain information that we, with us being placed in the same environment and given the same data, would not be able to duplicate without the use of external technological aid, and therefore not experiencing the full scope of data which could be collected if our senses were not as limited. This limitation within senses results in us not being able to grasp full truth in terms of our environment.
There is variation even within the scope of human sensory input capabilities, therefore they are not the same all the time. Humans do not have uniform senses and therefore some sense differently from others. This variation in human senses then provides those with more nimble senses more information about their surroundings, and restricts those with less nimble senses to less, withholding them from the wholeness of the “truth” of their surroundings. This is due to a variation in the human sense receptors themselves. Some may have the ability to sense a wider spectrum of the environment than others. Scientist’s latest studies have shown that there is considerable genetic variation in our ability to smell. It has been recently discovered that “Widespread phenotypic diversity in human olfaction is, in part, attributable to prevalent genetic variation in OR genes.” (Hasin-Brumshtein, Lancet and Olender), that each human has up to 800 receptors for various receptors for different chemicals but we do not have the same repertoire due to genetic differences, leading to some being able to detect certain chemicals while others can’t. Charles Wysocki, a neuroscientist at the Monell Chemical Senses Center in Philadelphia claims that this derives from the nasal epithelium, and when the ability to smell a specific substance is missing, so is the response in the brain. This can be traced back to the receptor - when you can’t smell a substance, the most likely explanation is that the receptor for it is not expressed well. (McKernan) The smell of freesias is a classic example, an estimated 10 per cent of the British population is unable to detect this flower's scent. Since our senses are variated from person to person, others would have a wider spectrum of information to work with and may come up with other hypotheses on the same environment, rendering it hard to trust our senses to give us truth in the objective sense.
In most cases, sense perception is essential for us to gain some evidence to support our knowledge claims, whether this evidence may be trusted or not, corroborating with our past personal experiences. However at times, our senses may deceive, warp and disfigure in the form of sensory perception, affecting our judgement of truth. One must involve other ways of knowledge to accurately achieve perceptive yet insightful procurement of knowledge, and senses cannot function as an independent entity to provide us with truth.
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Bibliography
Schnädelbach, Herbert. "Transformations of the Concept of Reason." Ethical Theory and Moral Practice. 1.1 (1998): 3-14. Web. 14 Apr. 2012. <>.
Dorland, W. A. Newman . Dorlands Illustrated Medical Dictionary. 26th ed. Philadelphia: Saunders, W B Co., 1981. Print.
David, Marian, "The Correspondence Theory of Truth", The Stanford Encyclopedia of Philosophy (Fall 2009 Edition), Edward N. Zalta (ed.), <>.
Hoffman, Louis. "Postmodernism Dictionary." Post-Modern Philosophy. 2008. Web. 15 Apr 2012. <>.
Alston, William P. “The reliability of sense perception.” Ithaca, NY: Cornell University Press, 1993. Print.
Des Cartes, “Philosophical Works”, Vol. 1, pp. 145-6. Cambridge University Press.
Ruth, McKernan. "Science: Advanced smelling tests: Ruth McKernan follows her nose to discover a fragrant world of complex sensory experiences."Independent [London] 20 12 1993, n. pag. Print.
A. Fraser and K. J. Wilcox: Perception of illusory movement. Nature, 281, 565-566, 197
Holtz, Brian. "Knowledge." Human Knowledge - Foundations and Limits. N.p., 06 09 2005. Web. 18 Mar 2012. <>.
"Frequency Ranges." EVP Frequency Ranges. SPI - Society for Paranormal Investigation, n.d. Web. 15 Apr 2012.
Hasin-Brumshtein, Yehudit, Doron Lancet, and Tsviya Olender. "Human olfaction: from genomic variation to phenotypic diversity." Trends in Genetics. &.x n. page. Web. 15 Apr. 2012. <>.
Van De Lagemaat, Richard. Theory Of Knowledge for the IB Diploma. 7th. Cambridge, UK: Cambridge University Press, 2010. 86-87. Print.
John Cage, “Defense of Satie,” John Cage, Richard Kostelanetz, editor (Praeger Publishers, 1970), p. 81.
Shultis, Christopher . "Silencing the Sounded Self: John Cage and the Intentionality of Nonintention."Musical Quarterly. 79.2 (1995): 312-350. Print.
