Hume's ultimate goal in his philosophic endeavors was to undermine abstruse Philosophy. By focusing on the aspect of reason, Hume shows there are limitations to philosophy. Since he did not know the limits, he proposed to use reason to the best of his ability, but when he came to a boundary, that was the limit. He conjectured that we must study reason to find out what is beyond the capability of reason.
Hume began his first examination if the mind by classifying its contents as Perceptions. "Here therefore [he divided] all the perceptions of the mind into two classes or species." (27) First, Impressions represented an image of something that portrayed an immediate relationship. Secondly, there were thoughts and ideas, which constituted the less vivid impressions. For example, the recalling of a memory. From this distinction, Hume decreed that all ideas had origin within impressions.
From the distinction of perceptions, Hume created his microscope' in order to trace all ideas back to impressions. He did this to search for the limits. If an idea could not be traced back to its impression, it was too abstruse. Hume separated the objects of human reason into two categories. First, the relation of ideas, which represented all that is a priori'. Secondly, he created the category of matters of fact. Matters of fact made up the a posteriori' piece of the spectrum of reason. Matters of fact are contingent, meaning they could be otherwise.
In order to go beyond the objects of human reason, Hume proposed that reasoning was based upon cause and effect. Causal relations help us to know things beyond our
immediate vicinity. All of our knowledge is based on experience. Therefore, we need experience to come to causal relationships of the world and experience constant conjunction. Hume stated that he "shall venture to affirm, as a general proposition which admits no exception, that the knowledge of this relation is not in any instance, attained by reasonings a priori', but arises entirely from experience." (42)
Unfortunately, our experience of constant conjunction only tells us about the past. Rationally, that is all it tells us. We can expect the effect to follow the cause, but it is not a sufficient basis to assume the effect will come from the cause in the future. These things are contingent- they could be different. "The connection between these two propositions is not intuitive it is always inferred." (480)
Hume asserted that the future will resemble the past. This is the assumption underlying all our ideas of causality. If the future does not resemble the past, then all our reason based on cause and effect will crumble. When Hume proposed questions such as "Is there any more intelligible proposition then to affirm that all trees will flourish in December and January, and will decay in May and June?" (49), Hume demonstrates that it is not a relation of ideas that future will resemble the past; it is possible that the course of nature will change. Therefore, what happens in the future is neither a relation of ideas, nor a matter of fact. "It is impossible, therefore, that any arguments from experience can prove this resemblance of past to future, since all these arguments are founded on the supposition of that resemblance."(51)
Now Hume proposed that all inferences come from custom, not reasoning. Through custom or habits, we have become accustomed to expect an effect to follow a
cause. This is not a rational argument. This argument centers on the theory of constant conjunction, which does not fall under either fork of reason. "All inferences from experience, therefore, are effects of custom, not reasoning."(57)
Hume analyzed the idea of causality by emphasizing the three demands that can be verified through observation. First he argued the aspect of constant conjunction. In this...