It seems more likely to agree with the argument that some qualities, such as primary qualities, are perceived equally by people. However, secondary qualities – which refer to an object’s individual perception of primary qualities – are perceived differently. George Berkeley denies the existence of material substance and argues that an object’s primary qualities are ideas” that form a material substance he calls secondary quality. On the other hand, Rene Descartes presents the theory of primary qualities as objective characteristics of an object and secondary qualities as subjective properties of material substance.
Berkeley’s concept has a problem with perceiving one particular object similarly by most people. If material subject is an idea, then people cannot have similar ideas simultaneously since ideas are subjective conceptions.
According to George Berkeley, there are no material substances. Instead, he distinguishes between ideas and souls, which are parts of human consciousness. Ideas are qualities that humans perceive subjectively while souls are immaterial subjects of spiritual activities. Berkeley believed that ideas are passive while souls are active, an important issue when arguing against his theory. This means that he does not assume material objects appear only due to perception and disappear when perception stops.
Idea” is the central object in Berkeley’s studies. Due to the explanations above, “quality” becomes a subjective concept as well. Thus, primary quality for Berkeley is the property of the idea itself rather than some material substance.
Material substance is nothing more than a combination or complex of ideas and thus secondary according to Berkeley. The set of qualities and properties determine material substance rather than being determined by it.
Berkeley reduces the concept of “qualities” to sensations so that the surrounding environment and world reduce to an aggregate of individual sensations for each cognizant person.
Berkeley concludes that humans perceive only their personal sensations/feelings making cognition of the real objective world theoretically impossible.
According to Berkeley, what we experience through our senses is due to God’s direct action; it is through our senses that God communicates with us about what things are good or harmful for us (p.69).
We see then that Berkeley’s epistemology is providential in all knowledge being provided by God-The-Instructor transmitted through our senses (p.18)[1][2].
Unlike Berkeley, Descartes attempted to prove the existence of corporeal objects. According to Descartes, material substance exists and has primary and secondary qualities. Secondary qualities are distinguished based on things that can differ from person to person, such as color, taste, and smell. These qualities exist only in the minds of observers and are not inherent in the object itself. Primary qualities include anything that can be measured or have mathematics applied to it, such as size, shape or motion.
Descartes argued that secondary qualities are individual perceptions of primary qualities belonging to a particular material substance. On the other hand, shape, motion speed and size belong inherently to the object itself without being dependent on an observer’s mind.
In Descartes’ theory of perception of things, primary and secondary quality distinctions stem from extension or existence in space. All primary qualities necessarily belong to an object while secondary ones do not necessarily belong but depend on an observer’s perception.
Descartes proved existence in space through his methodical doubt where he doubted everything he had heard seen or touched until he concluded that if he thought then he existed (p25). This proof was for the existence of primary qualities like material objects themselves.
Another way Descartes proved the existence of material substances is by showing that pure intellect is entirely controlled by will while imagination is not controlled by will (p36)[3]. Therefore anything can be easily ignored while imagination cannot be restricted; thus matter must exist because without subsistence there would be no imagination.
Berkeley and Descartes agree that the perception of secondary qualities, such as taste, smell, color, and temperature, are types of pleasure and pain. As pleasures and pains cannot exist without perception or an unperceiving substance, it follows that these things are not qualities of physical objects and therefore cannot exist without the mind. Both philosophers consider these qualities to be individual perceptions.
However, Berkeley denies the existence of material objects while Descartes believes that the existence of material substance in space is a primary quality. According to Descartes, one material object cannot have two incompatible qualities at the same time (e.g., hot and cold). On the other hand, Berkeley argues that an immediately perceived quality is really a quality of the perceived object. Additionally, if there is a change in quality then there must be a change in object.
Berkeley responds to Descartes’ argument by stating that shape and size depend on eye position while solidity depends on touch. The idea of motion is always relative to some particular situation.
Both primary and secondary qualities can be represented through ideas or sense-data. However, according to Descartes only sense-data for primary qualities can actually represent primary qualities; sense-data for secondary qualities do not represent them because they do not exist in objects at all. Instead we might say that secondary quality refers exactly to the same thing as sense or feeling of a secondary quality [4].
I tend to support Descartes’ argument more. If there were only ideas and no material substance, how could it happen that people perceive some things similarly and others differently? If Berkeley’s theory were true, then everything in the world would be perceived differently. Each human being would have a different view of the same material or immaterial objects. However, people usually perceive size, shape, and motion similarly. Therefore, it is impossible to assume that there are only ideas” without their physical existence.
I agree with the idea that primary qualities such as existence in space, material characteristics like size and shape, and speed are viewed equally by people. However, secondary qualities such as smell and taste differ due to different perceptions. I tend to distinguish between qualities that belong to the physical object itself and those that humans create in their minds to characterize the material substance.
I think the main problem with Berkeley’s arguments is that there are no strong strict criteria by which people determine the qualities of a physical object. It is not understandable why primary qualities are perceived equally while perception of secondary qualities differs from person to person.
If there were no material world and people did not actually touch, see, hear or feel but only perceived “ideas,” then how could 100 respondents all say a book has a square form but call its color by different names ranging from light blue to dark blue? Additionally, only primary qualities are inseparable from their subjects; you can imagine any object in different colors or with different tastes but cannot imagine them losing their shape.
For example: A brown cat turning black cannot be imagined not in cat shape; it is also impossible to imagine a material substance without secondary qualities although it’s hard imagining an object without primary attributes like shape or size.It’s obvious when sounds aren’t heard they do not exist (even ultrasounds which aren’t heard by people are heard with special devices). I tend to assume that the material substance is characterized by the collection of primary and secondary qualities but deny the theory that a set of qualities and properties determine an object.
After presenting two opposite arguments concerning primary qualities and the existence of material substance, I conclude that perceiving things similarly makes it impossible to conceive of the absence of a material world and the existence of ideas alone. Berkeley insists that primary qualities are properties of ideas, not material substances. He believes there is no physical world or surrounding environment; everything in the world is just ideas and our perception. According to him, idea” is the primary quality, and material substance is secondary. The complex of “ideas” forms a material substance. Feelings and sensations are his only reliable sources for information.
Berkeley believes that God creates criteria for people to distinguish, compare, and interpret obtained information about objects. Each human being can perceive things differently according to their knowledge and criteria.
Descartes sees definite distinctions between primary and secondary qualities of an object. For him, primary objects are properties objectively measurable only in one way belonging to a material substance.
However, he agrees with Berkeley’s idea that there are secondary qualities which do not belong to an object but are products of a person’s mind; they can be viewed differently by people as they are subjective while primary qualities remain objective.
In my opinion, Berkeley has an extreme point-of-view while Descartes presents a more balanced perspective on this matter.
Bibliography
1. Will Durant’s Story of Philosophy: The Lives and Opinions of the World’s Greatest Philosophers” is a reissued edition from 1991.
2. George Pitcher’s book The Arguments of the Philosophers” was published by Routledge and Kegan Paul Books in 1989.
3. Benedictus de Spinoza’s Principles of Descartes Philosophy” was published by Open Court Pub Co in 1983.
References:
- George Pitcher, Berkeley (The Arguments of the Philosophers), pp. 14-17
- Will Durant, Story of Philosophy: The Lives and Opinions of the World’s Greatest Philosophers, pp. 68-75 and 85-87
- Benedictus de Spinoza, Principles of Descartes Philosophy, pp.16-18 and 24-37
