|Your associate does not realize that although his values differ from yours, they are no more valuable than yours. |
Values are deep-seated beliefs, and most people inherently believe that theirs are right, true, and appropriate. As many researchers have found, values are quite stable over time and do not change quickly or easily. Although there are many examples of people whose values have changed dramatically, this is often the result of major life-changing events, and not the result of constant hounding by a co-worker.
In fact, there are even some questions about people who feel the need to constantly proclaim their values. One wonders if they are trying to convince others or themselves as to the worth of their values.
Either way, you should tell this associate that you are not interested in participating in the debate, but would certainly be willing to talk with him about other topics, such as work. Whenever he tries to draw you into a joust of values, do not engage. Doing so will only encourage him. The larger picture is that this is an individual who has brought a good deal of baggage to work. If he keeps up the present behavior, he may not even need to unpack.