Making a Mountain...

Aristotle and Aquinas: The Vital Difference by Don DeMarco, Ph. D.

As far as I'm concerned, personalism is not a significant difference between the ethics of Aquinas and that of Aristotle. (We might even ask the question of whether contenmporary personalism is even important to the moral theology of Aquinas, or if we are just trading one word, e.g. human, for another, person.)

"The difference between the ethics of Aristotle and Aquinas has to do with how virtue comes about. It is reasonable to be virtuous. Surely “honesty is the best policy.” That is simply a reasonable statement that does not require love. And virtue, for Aristotle, lies between two extremes. Thus, the virtue of courage, for example, is the midpoint between the vices of timidity and foolishness. This is all very sensible, though something is missing.

Perhaps Aristotle overestimated our capacity to be reasonable and under-estimated the importance of love. Whereas Aristotle links virtue to reason, Aquinas links it more properly to love. Therefore, as the Angelic doctor states, “Love is the form of all virtues.” This means that every virtue derives its degree of virtuousness by its association with love."

The important difference is that Aristotle writes from a non-Christian perspective, one which is unaided by Divine Revelation. Aristotle does not talk about "love" but he does talk about friendship in all of its forms, as it exists between human beings. But not, friendship between man and God. Should we be surprised then that he has no understanding of the beatitude to which we are called, or the grace that is necessary? No account of the "supernatural organism" which is so central to the moral theology of Aquinas (and of good Christian moral theology in general)?

The differences in their ethics is not due to competing accounts of human nature (with respect to the material or formal causes) - but with respect to human nature as it relates to its Creator, God.