According to Scripture, human reasoning is both finite, or limited in its capabilities and also fallen, or conditioned by moral corruption, even as it is governed by presuppositions. Presuppositions are beliefs upon which our reasoning is based, or as one philosopher stated “controlling beliefs that determine what we think.” The “what” in that previous definition is also synonymous with “how.” By definition a presuppositional analysis places stress on the rational connections between beliefs and reasoning. But such an analysis is always done by a person who is dependent on their own finite and fallen reasoning for their presuppositional analysis.
Our finitude means we are limited in particular ways. The truth that we are morally fallen highlights that we are blinded to particular realities and in this spiritual and moral blindedness we fail to love and honor God as God, and fail to love and serve our neighbor for who he or she is. There is an incapacity that sin saddles us with and this is inextricably joined to what we willingly choose. We are willfully blind to particular realities because of our sin. In our sin we have a vested interest in not seeing our sin. Among other things, this means that in our sin we have a vested interest in not dealing honestly with our presuppositions or those of others.
Those who are prone to stress a presuppositional analysis of other people’s thinking are prone to cut-off their investigation of those people’s thinking when and to the degree that they are satisfied for whatever reason (and these can be numerous and perhaps even often unknown to us) that they have sufficiently understood the rational connections existing in those people’s thinking. Thus, when John has to his satisfaction sufficiently understood Bill’s reasoning based on John’s presuppositional analysis of Bill’s reasoning, John believes himself to have a better understanding of Bill’s reasoning than Bill has of his own reasoning. Now, it is possible that John may very well have in various ways and to varying degrees a better understanding of Bill’s reasoning than Bill has of his own reasoning. But it is also true that John may be mistaken at particular points in his presuppositional analysis of Bill’s reasoning. Furthermore, John is also subject to a presuppositional analysis.
A friend of mine once wrote a rather provocative song about some of these things and in it he sung, “I am trapped within my reason.” Well, at least some people recognize some of the legitimacy of that statement. You see, it may be that in his presuppositional analysis of Bill’s thinking that John is simply imposing his own pattern of thought upon Bill. Perhaps this helps, at least in part, explain some of the doctrinal disputes that mark some sectors of the Church, both now and throughout history. And, oh, by the way, people can’t be reduced to their reasoning. Think about it.