Where Does Objectivity Come from?

I have talked about Hume’s interpretation of moral actions, which are caused by human passions and emotions. The reason why we go to save the kid falling into the well is that we cannot bare seeing the scence and feels tortured at the picture. In other word, we don't do virtuous actions because of reasoning and refecting, but something rooted in our human nature that is called emtions. Then it is a problem for him regarding how to argue against those whose emotions are different from normal people. And I think Kant’s interpretation of rationality can be helpful for us to do that job.

Kant starts with the notion of “good will”, and good will is intimated related with rationality. One essential point for us to understand the objectivity of morality in Kantian can be made clear by differentiating between humanity and rationality. For Kant, the objectivity of the goodness of human will does not consist in humanity, because human weill is only subjectively imperfect. (Grounding of morality, 414) In addition, Kant claims that the reality of moral principle cannot be derived from the special characteristics of human nature:

For duty has to be a practical, unconditioned necessity of action; hence it must hold for all rational beings and for this reaon only can it also be a law for all human wills. On the other hand, whatever is derived from the special natural condition of humanity, from certain feelings and propensities, or even, if such were possible, from some special tendency peculiar to human reason and no holding necessarily for the will of every rational beings— all of this can indeed yield a maxim valid for us, but not a law. This is to say that such can yield a subjective principle according to which we might act if we happen to have the propensity and inclination, but cannot yield an objective principle according to which we would be directed to act eventhough our every propensity, inclination, and natural tendency were opposed to it. (G, 425)

While the Hume’s interpretation of morality regards human dispositions and natural conditions as the most fundamental elements in our thinking and action, Kant thinks very differently. First, humanity has its grounding in rationality because rationality holds fro all rational beings including human beings as one of the species. While humanity has in its root both subjective inclinations and rational capacities, Kant’s conception of rationality is a transcendent and a priori capacity, without any subjective consitution. Kant does not deny that dispositions and feelings can lead us to make right choice, but he is strongly objecting to grounding moral judgment only on humanity, since it is is subjectively imperfect because of its special inclinations and dispositions.

In addition, Kant regards the rationality used as tools and means to get to another purpose as only contingetn and arbitary. Such rationality is what Williams uses to satisfy the actualization of agent’s projects and desires. But for Kant, “rational nature exists as an end in itself”, (G, 437)and only this kind of rationality is the grounding of categorical imperative. Kant claims that the practical imperative will be that “Act in such a way that you treat humanity, whether in your own person or in the person of another, always at the same time as an end and never simply as a means.” (G, 429) Other imperatives and rational capacities manipulated for other purposes rather than themselves are only hypothetical, which means they are always under the test of universal law and have to practical necessity. Thus we can see that what draws the line between the Kantian and the Humean moral philosophy is that Kant provides an objectvie grounding of human nature in terms of univeral rationality, while Hume does not appeal to anything beyond the disposition and feelings withn human nature.