If we take moral reasoning to mean consistency of judgment with principles, then Kantian ethics would be reasonable insofar as one applies Kantian principles to one's moral judgments. For instance, if one of your principles is the categorical imperative, then you would be reasonable if you applied it to your moral decisions. Kantian ethics have been interpreted by some as being rooted in emotion. See here:

http://www.wjh.harvard.edu/~mcl/mcl/pubs/Greene-KantSoul.pdf