The mind and the senses: essential components for all knowledge.

April 7, 2003

(Note: the empiricism mentioned in this essay in not the same as Locke's empiricism. The differences are recognized as "possible pitfalls" in the essay.)

1. I believe that out of the three positions studied in class, the empiricist position comes closest to the truth.  Properly understood, empiricism presents the right standard for true knowledge as well as the correct process by which truth is determined.  A potential weakness of empiricism is to overlook the role of the mind in converting simple sense impressions into knowledge by failing to fully recognize the contextual nature of knowledge and thus making a false distinction between primary and secondary properties.  Such a view should be amended to more precisely define the role of the mind in interpreting sense date and forming concepts from sense impressions.

2. Empiricism starts with two important principles: that senses are the only source of information about reality and that the mind is a blank slate at birth.  The basic assertion of empiricism is that senses are the only thing needed for to obtain knowledge about reality, and the mind is only the means by which sensory data is converted into knowledge, not a tool of perception itself.  This position rejects a number of other traditional sources of knowledge, such as divine revelation, innate ideas, sixth-sense intuition, and rationalism.  The task for the empiricist is then to determine how sense data is converted into true knowledge, and how knowledge may be verified and reduced back to sensory inputs.  In order for knowledge itself to be possible, the empiricist must affirm show that the universe is causal and exists independently of the mind.  Without these basic assumptions, no true knowledge is possible, since “truth” would be relative to each individual’s mind.  Furthermore, if knowledge were not obtained by a causal process, then the idea of proof itself would be meaningless. 

3. The empiricist position holds that supernatural sources of knowledge can be rejected because there isn't any evidence of such otherworldly guidance.  Likewise, there is no evidence that children inherit ideas from parents or ancestors before birth.  However more fundamentally, a major strength of the empiricist position is that any proof against the senses must contradicts itself because it must assume that sensory inputs are valid.  For example, someone claiming to be able to read minds would have to assume that his audience is real, that the words reaching his audience are the same ones as the ones he is hearing come out of his mouth, and that the same mind reading method he tries today will work tomorrow.  The last assumption relies on a causal theory of perception – the same sense organs and the same inputs, will produce the same sense perceptions every time.  Without accepting a causal reality and valid senses, the idea of “proof” is meaningless.

4. If all knowledge must be based on the evidence of the senses, than the mind must start as a blank slate at birth, and base all knowledge on an inductive process.  Here, the rationalist may claim that mind reaches conclusions about many abstract ideas that are not directly presented by the senses.  He might say that knowledge of things such as mathematics, politics, and history does not come from direct sensory evidence.  In order for the empiricist to have a concrete theory, he must first explain the process by which knowledge is derived from sensory data.  The inductive process presented in class is a major strength of the empiricist position because it is the only position to firmly connect knowledge to reality by a specific process.  Because a possible pitfall of empiricism is to ignore the role of the mind in forming concepts by assuming that knowledge is a passive process of “absorbing” information from reality, a proper account of the process of knowledge-formation must account for the contextual nature of knowledge. 

5. The method by which raw sensory data is converted into useful concepts that may include any number of instances, is key to the empirical theory of knowledge.  For an example of the method, consider an orange.  Visual sensory data presents an orange blob that is oval in shape, with a dark border on one side (the shadow).  This is all that the sense organs are able to present, as they do not have any ability to interpret the data that they convey, and the mind does not have the ability to affect sense perception.  No amount of wishing or thinking will change the fact that certain photos are hitting one’s eyes and causing certain chemical reactions, and send specific electrical impulses to the brain.  Upon receiving the visual data, the perceptual part of the brain converts the simple sense impressions of the orange blob into the perception of a round object by combining different elements (the oval shape, the shadow, the orange color, the cellular texture) into a single perceived object -- an orange sphere, a few inches in diameter.  This is done by an automatic process (learned by every human at a very young age) of recognizing solid objects and distinguishing them from the rest of reality.  At this point, it is as if the orange is being seen for the first time – the mind’s perceptual faculties alone do not know if they are seeing an inflatable toy ball, a weird egg, or a fruit.  Only after the orange is recognized as a distinct object by the mind’s perceptual faculties, the conceptual part of the brain notices the similarity of the object’s properties to other objects it has seen before, in the concept it has labeled as “orange.”  This is possible because the mind is able to abstract away the variations between different oranges that it has observed, and recognize the similarities between different instances of the single concept “orange.”  Once the object being observed is recognized as an instance of the set “orange,” we “realize” that the object being observed is in fact an orange, and attribute all the properties of taste, feel, and smell that we normally associate with oranges.

6. An important characteristic of the process of recognizing an object is that the process is not automatic.  The concept of “orange” is not contained in the object itself, and does not automatically present itself to the mind, but is rather the result of a complex process of sense perception and conceptualization.  A corollary is that everything that is perceived, must be perceived within the context of the nature senses feeding data to the minds conceptual faculties:  no form of sense-independent perception is possible, and all valid knowledge must be based on an inductive process of interpreting sense data and converting them to concepts.

7. A possible pitfall of the empiricist position at the point of forming concepts is to fail to recognize the role of the mind in converting sensory data into knowledge by making a distinction between “true” and observed reality.  According to this view, objects posses two kinds of properties: primary and secondary.  Primary properties are the “true” nature of perceived objects, while secondary properties are consequences of the primary properties that vary according to the nature of the observer. However, this position confuses concepts with perceptions: the difference between primary and secondary properties is not a matter of fundamentally different properties, but the difference between concepts and sense-perceptions.  In the example of the orange, the empiricist may claim that certain properties are objective and unchanging (the size, mass, molecular structure of the orange) while others vary according to the observer’s perspective and sense organs (feel, color, smell.)  However, even “secondary” properties are objective within the context of the particular sense organ and perspective of the observer.   Furthermore, the round shape of the orange is not perceived directly: we do not see the orange from all sides, just as we cannot see a square building from all sides at once.  Whatever is perceived, must be perceived as raw sensory data according to the nature of the perceiving sense organ, and the conclusions reached about the object being observed must be contextual to nature of senses making the observation.  As we approach a tall building, it takes up a larger and larger amount of our vision, but does that some property of the building varies according to our distance from it?  No, the “visual size” of a building varies according the rules of perspective, which is what allows us to grasp the size and shape of the entire building in our mind even though we cannot see it all at once or perceive such a thing as a “square” or a “sphere” directly.

8. A similar argument that can be presented against the validity of the senses in forming knowledge, is that the senses can only present a limited and biased view of reality.  In the case of the orange for example, normal human senses can directly observe only the physical dimensions, texture and taste of the orange.  On a biological level, many other properties can be derived, which explain the orange’s composition and formation on a more basic level.  On the atomic level, the properties of an orange are explained on an even more fundamental level.  The atomic level itself may be explained by ever more minute interactions of basic particles.  Which level represents the “true” nature of an orange?  The empiricist’s answer is (or should be) that each perspective is equally valid within its own context, and a context-less perspective of the orange is not only impossible, but also meaningless.  If we somehow determined the precise sub-atomic composition of an object, but did not know anything about it on the scale of everyday life, we would know whether it hot or cold, edible or poisonous.  All knowledge is therefore contextual, and equally valid within each context.

9. Another objection to empiricism is the existence of higher abstract concepts such as numbers and laws of physics that do not have any directly observable counterparts in physical reality and cannot be deduced directly from observation.  Since the empiricist holds that there is no such thing as innate concepts, he must be able to explain how such concepts are derived from perceptual inputs.  He can do this with numbers by showing that a number is just like any other concept, only one that can be applied to any set of objects, rather than one particular kind.  For example, a single apple is an instance of the abstract concept of “one.”  An apple, an apple, and an apple is an instance of the concept “three.”  By abstracting away the differences between two different concepts, say, an apple and an orange, we can come to hold the more complex concept of “fruit.”  The same general process that is used to derive a simple concept can be extended to ever more complex categorization of knowledge until it accounts for the whole scope of human knowledge.  In such a way, the empiricist can demonstrate that all of human knowledge has a sensory connection to reality and that knowledge can only be valid if it is based on the process of perception and conceptualization of data received from sensory inputs.

10. Thus, by demonstrating that all human knowledge must be based on sensory data and explaining the process of perception and concept-formation, the empiricist can form a solid case for his position.  Because he is able to show how all knowledge is derived from sensory data, any refutation of empiricism becomes contradictory, for the concept of proof itself assumes that the senses are a valid way of obtaining knowledge.