Theories in Epistemology: Are Our Senses Reliable?

Searching for Knowledge
Searching for Knowledge. H. Armstrong Roberts/ClassicStock/Archive Photos/Getty

Although empiricism and rationalism exhaust the possible options for how we acquire knowledge, that isn't the full extent of epistemology. This field also addresses questions about how we construct concepts in our minds, the nature of knowledge itself, the relationship between what we "know" and the objects of our knowledge, the reliability of our senses, and more.

Minds and Objects

In general, theories about the relationship between the knowledge in our minds and the objects of our knowledge have been divided into two types of positions, dualistic and monistic, though a third has become popular in recent decades.

Epistemological Dualism: According to this position, the object "out there" and the idea "in the mind" are two entirely different things. One might have some similarity to the other, but we shouldn't necessarily count on it. Critical Realism is a form of Epistemological Dualism because it subscribes to the view that there is both a mental world and an objective, outside world. Knowledge about the outside world may not always be possible and may often be imperfect, but nevertheless it can, in principle, be acquired and it is essentially different from the mental world of our minds.

Epistemological Monism: This is the idea that the "real objects" out there and the knowledge of those objects stand in close relationship with each other. Ultimately, they are not two entirely different things as in Epistemological Dualism - either the mental object is equated with the known object, as in Realism, or the known object is equated with the mental object, as in Idealism. A consequence of this is that statements about physical objects only make sense if they can be construed as really being statements about our sense data. Why? Because we are permanently cut off from the physical world and all we really have access to is our mental world - and for some, this entails denying that there is even an independent physical world in the first place.

Epistemological Pluralism: This is an idea which has been made popular in postmodernist writings and argues that knowledge is highly contextualized by historical, cultural and other outside factors. Thus, rather than there being simply one type of thing as in monism (either essentially mental or essentially physical) or two types of things as in dualism (both mental and physical), there exists a multiplicity of things which affect the acquisition of knowledge: our mental and sensory events, the physical objects, and the various influences upon us which lie outside of our immediate control. This position is also sometimes referred to as Epistemological Relativism because knowledge is construed as relative to different historical and cultural forces.

Epistemological Theories

The above are only very general ideas about the sort of relationship which exists between knowledge and the objects of knowledge - there are also a variety of more specific theories, all of which can be categorized in the above three groupings:

Sensationalistic Empiricism: This is the idea that the things we experience, and only those things, are the data which constitute our knowledge. What this means is that we cannot abstract away from our experiences and acquire knowledge that way - this only results in speculation in some form. This position was often adopted by logical positivists.

Realism: Also sometimes called Naive Realism, this is the idea that there is a "world out there" independent of and prior to our knowledge, but which we can grasp in some way. This means that there exists certainties about the world which are unaffected by our perception of the world. One of the problems with this view is that it has difficulty in differentiating between true and false perceptions because it can only appeal to perception itself when a conflict or problem arises.

Representative Realism: According to this position, the ideas in our minds represent aspects of objective reality - this is what we perceive and this is what we have knowledge of. What this means is that the ideas in our minds aren't really the same as those in the outside world, and hence differences between them can result in a false understanding about reality. This is also sometimes referred to as Critical Realism because it adopts a critical or skeptical position towards what can or cannot be known. Critical Realists accept the arguments from skeptics that our perceptions and our cultures can color what we learn about the world, but they disagree that therefore all knowledge claims are worthless.

Hypercritical Realism: This is an extreme form of critical realism, according to which the world which exists is very dissimilar to how it appears to us. We have all sorts of erroneous beliefs about the way the world is because our ability to perceive the world is woefully inadequate to the task.

Common Sense Realism: Also sometimes referred to as Direct Realism, this is the idea that there exists an objective "world out there" and our minds can somehow acquire knowledge of it, at least to a limited extent, with the ordinary means available to ordinary people. Thomas Reid (1710-1796) popularized this view in opposition to the skepticism of David Hume. According to Reid, common sense is perfectly adequate for deducing truths about the world, whereas Hume's works were simply one philosopher's abstraction.

Phenomenalism: According to various sorts of phenomenalism (also sometimes known as Agnostic Realism, Subjectivism, or Idealism), knowledge is limited to the "world of appearance," which should be distinguished from the "world in itself" (outside reality). As a result, it is argued that our immediate sense perceptions are only evidence of sense perceptions and not of any objectively existing physical objects.

Objective Idealism: According to this position, the concepts in our minds are not simply subjective but are instead objective realities - however, they are still mental events. Although objects in the world are independent of the human observer, they are part of the mind of an "absolute knower" - in other words, they are events in the mind of .

Skepticism: Formal philosophical skepticism denies, to one degree or another, that knowledge of anything is possible in the first place. One extreme form of this skepticism is solipsism, according to which the only reality is the realm of ideas in your mind - there is no objective reality "out there." A more common form of skepticism is sensory skepticism which argues that our senses are unreliable, and hence so are any knowledge claims which we might make based on sensory experience.