To begin with, let me explain the meaning of the two structures. According to the Oxford dictionary, a raft is a flat buoyant structure of timber or other materials fastened together, used as a boat or floating platform whereas a pyramid is a monumental structure with a square or triangular base and sloping sides that meet in a point at the top, especially one built of stone as a royal tomb in ancient Egypt. In this case, for a raft several structures of timber have to be joined together in order to be useful in supporting something real. For instance, once the structures are joined together you can use them as a boat to cross over a lake otherwise with one piece of timber this can not be possible. Under this circumstance, if one or two pieces of timber break then it means that the raft can’t function efficiently and the whole boat will need to be serviced before it can be used reliably. On the other hand, looking at the pyramid with a very sharp end and a broad base, it is easier to rest it with the broad end at the bottom or else it will not be stable if rested on the sharp end.
From this understanding, in relation to knowledge coherentism hereby represented by raft can be seen as a case where several beliefs are joined together to support a truth. This is to mean that, a single belief cannot yield to a truth by its own. I addition the beliefs must be related in order to be justified. For example, to be considered a successful candidate one has to perform well in all subjects. Additionally, for one to be able to graduate a certain course he or she is expected to undertake all the required units. On the other hand, foundationalism as represented by pyramid is a case whereby a single belief forms a basis for the justification of other beliefs. However this may not be true thus complicates knowledge. A case in point is where it is generally believed that all white people are from the Western world. It may be true to say that Americans are Western but we cannot be justified to say that albinos who are also white are Western.
Above and beyond, coherentism and foundationalism differ in the sense that the former is based on experience whereas the latter is on thought. Generally, lessons out of experience are more justified than those thought of. It is not the case that whatever you think of is a reality until you go through it. The best knowledge in life is gained by experience. The fact that your parents are brilliant and successful does not guarantee one to make it in life; you have to face it by yourself. And if you are to rely entirely on your parents then you can be assured of dying a poor man.
Coherentism can be perceived to be more reeliable as it is action oriented rather than foundationalism which is only based on ideas. A sequence of events in life can yield to positive changes in knowledge. On the contrary ideas will only create a false image which may not stand in reality. For the ideas to be true they have to be acted upon. Debatably on this point, for any action that is undertaken, it has its basis on a certain idea, thus the complexity in knowledge.
Additionally, coherentism is established on facts, and thus we can have confidence that anything factual is justified. Beliefs that have been tried and proved as a fact are able to promote our understanding of certain issues in life. This is not the case for foundationalism which is created on principles and set up on people’s opinions. In the olden days people made decisions based on past experiences of life and especially with regards to weather conditions. Based on these principles farmers could till their lands with the belief that it would rain.
To wind up these issues of coherentism and foundationalism in determination of knowledge, the two concepts remains a debatable subject. The basis of both is a simple belief system; it is upon one to choose how to weigh the beliefs in justifying the truth by finding concrete reasons to the beliefs. Finally knowledge is power, be wise.