Kant argued that, in matters of perception, there is a noumenon and a phenomenon. The phenomenal world is that which a human can perceive. But the noumenal world exists independently of human perception. Something in the noumenal world is the thing-in-itself (das Ding an sich). Most critically for this question, the noumenal world is completely unknowable through the senses.
So the question is this: given that the noumenal world is unknowable through the senses, but the senses are all that a person has to make observations, then are decisions in the phenomenal world arbitrary in relation to the events in the noumenal world?