On Knowledge: A look at a priori/posteriori knowledge and universals

Knowledge of the world allows us understand relations between varies objects. It is essential for our day to day lives as well as for our broad global issues. Since knowledge is crucial for in our lives, it is important that we have an understanding of what this is. The term knowledge can be defined as a mental state that represents the world through sufficient evidence. The source of this evidence divides knowledge into two categories, a priori knowledge, and a posteriori knowledge. For knowledge that is a posteriori, evidence is derive from one's senses. Furthermore, knowledge of a subject is only obtain after coming in contact with it. For example, the sound of piano can only be known only after it has been experienced. To have knowledge a priori on the other hand, is to have knowledge before one comes in contact with a subject. An example of a priori knowledge would be 2+2=4.

This provides information about the world but is not obtained through the senses.

To categorize knowledge into two different categories, is not imply that the two are incompatible with each other. Having sensory experience does not preclude one from having a priori knowledge. These are simply two ways of labeling knowledge. It is possible that I can have a concept of a subject in my mind and and then have that concept further develop after experiencing the subject. Consider a person at a park looking for a bench to sit. He has knowledge a priori of a what a bench should look like, and then after he encounters a bench in the park he gains a posteriori knowledge of that specific bench in the park. Both categories of knowledge are used to enhance the information obtain from a subject.

Several people have deemed a priori knowledge impossible, and that the only source of knowledge is that of experience. English philosopher, Betrand Russell, countered these critics by providing his proposal of a solution. Contrary to traditional thought, Russell claimed that a priori knowledge is not just knowledge of one's thought but knowledge of the world. To support his claim he refers to the law of contradiction which states that something can't be both X and not X, where X represents any given subject. To understand that if a tree is a beech then, it can not also be not a beech, is to have knowledge of a truth about the tree. A tree that exist independent of the mind. Therefore, Russell concludes that a priori knowledge is possible through our capability to understand truths of a subject without the need to interact with it.

Knowledge has appeared up to this point to deal only with things in the world that in existence in time. As we proceed, it will be observed that we also are able to have understanding of things that do not exist in time. Consider the color blue. If I was ask what is blue? We may find ourselves recalling different objects that we would call blue in order to find something in common in all of them. This similarity would be found to be their blueness. It would be observed that blueness is shared amongst all the objects that we would recall to be blue, demonstrating also the repeatability of the similarity. Similarities with these characteristics of share-ability, and repeatability are defined as universals. Universals like blueness are the pure essences of particular things which particulars partake from. Particulars, which are not shareable or repeatable, are related to other particulars only through the universals they partake from. Meaning particulars such as a blue cup, a blue marker, and a blue bag are finite things which are related to one another through the universal blueness. Russell points out that universals can be qualities such as blueness which describe one feature in this case blue, or they can be relations. For example, the universal tallness can be used to describe the relation between an ant and an elephant as the elephant being taller than the ant. To simplify this in terms of language, it can be said that universal relations are any words that are prepositions, or verbs, while universal qualities are any words that are adjectives. Truth of a subject henceforth involves universals, and to have knowledge of truth, we must have knowledge of universals.

Russell's view on universals which can be defined as transcendent realism and which he derives from Plato's theory of the forms, is one in which the particulars partake from universals that exist or rather subsist outside of time and outside of of the world of things in a universal heaven. This idea is often compared to immanent realism in which universals exist only through the particulars that instantiate their property and unlike transcendent realism does not reside in a universal heaven. Russell denies nominalism which accepts universals only as terms to be spoken and not something of actual existences. For Russell, universals are very much real and are independent of one's mind. Russell argues that one can have a thought about a universal but the thought itself is not a universal as that same thought can not be exactly repeated again, and does not have the capacity to be shared. If one were to in which case declare that universals are a mental phenomena then the result would be multiple universals for the same subject. Russell also argues that universal relations could not be depended on our minds and requires there to be only one not several universals. Russell illustrates this point by considering the relation Edinburgh is north of London. The relation 'north of' would still exist regardless if one were to think about it or not. Therefore, in order for universals to function in the world, they have to be independent of our minds.

For Russell and other philosophers such as David Armstrong, the independence of universals of from our minds is key for our knowledge of the world. This point allows us to have knowledge about an object without having to resort relativism or skepticism. This view in which case is challenged by, Scottish philosopher, David Hume's account of causation. Before we consider this opposition let us define briefly what is causation and Hume's account of it. Causation can be defined as a relation between two events in correspondence with their cause and effect. For Hume causation is not a universal quality that something can partake from. Rather Hume asserts that what makes something a cause is it relation to its effects. He claims that causes must have three components, they have to have priority, be contiguous, and have a necessary connection. A cause has priority by coming before the effect. This is illustrated when I kick a ball. My foot comes first before the ball moves. Contiguity is possible if the cause and effect are near each other in space and time. When I kick the ball, I physically touch it establishing my nearness to it. Hume brings up this component of necessary connection which is controversial to Russell's transcendent realism. Necessary connection is the components that states that the cause and the effect have to go together, and that they are inseparable. If I kick the ball, it necessarily has to move. Hume argues that our knowledge of causation is obtain only through experience. Therefore we observe certain causes and effects grouped together and we generate ideas in our minds that a specific effect has to follow a specific cause. Hume concludes that such necessary connection is a manifestation in the mind. This as I have point out puts trouble on Russell's transcendent realism. Since necessity according to Hume is a mental phenomenon then that would lead one to conclude that universals themselves are mental phenomenons. Russell in the other hand had stressed the importance of universals and the need for them to subsist independent from our minds.

This controversy between these two views puts a strain on our knowledge of the world. Are we left then to decide between causation and universals? Or are we to somehow compromise both views. If the necessary connection is somehow not in our minds as Hume would otherwise claim, but in the world such that an effect B must follow after cause A, then we find the world to be more orderly and govern steadily by set laws. This in which case would contradict Russell's view of universals. For Russell claims that particulars partake from the perfection of universals and are therefore imperfect copies of the universals. How could imperfect particulars form such an orderly world? Are knowledge and understanding is thus is left in conflict.