Two of the most prominent philosophers of their times, David Hume and Immanuel Kant both gave great contributions to the foundation of thoughts that concern the metaphysics of morals. Hume, followed later by Kant's theories touched on different themes such as justice, freedom, the knowledge or metaphysics of value, and cause and effect. By first laying out the ideas of Hume and then Kant, to be in chronological order, I hope to gain a fuller knowledge as to the similarities and differences of each philosopher's beliefs. .
Hume's ultimate goal in his philosophic actions was to undermine obscure 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 stressed that we must study reason to find out what is beyond the capability of reason. .
Hume begins his examinations of the mind by classifying its contents as perceptions. Hume then divides all the perceptions of the mind into two classes or species. 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. In other words, 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. If an idea could not be traced back to its impression, it was too obscure. 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 conditional, meaning they could be otherwise.