Reason, to my mind, is a human universal (though some do it far better than others).
In other words, barring intellectual disability or brain injury, human beings have a universal capacity for reasoning with others: we can deduct, induct, experiment, offer reasons to one another, theorize, dialogue, analogize, make rhetorical appeals, argue with ourselves in solitude, calculate, and evaluate evidence.
When we do these things systematically, as in Baconian science, we can arrive at reasonable public conclusions about the world that all people, whatever their cultural backgrounds, are likely to recognize as true (at least on the premises that we can agree upon). This doesn’t mean that we all start with the same philosophical premises; it means that we can all follow one another’s rationales (so long as we understand the premises that we start from). Put another way, the methodologies of science and reason are not culture-bound and contingent; they are things that all human beings, in all places and times, are able to practice.
As a humanist, I believe that the rational and global human community—far more so than race, faith, or nation—represents our most hopeful, meaningful, and unifying concept. The university, not the church or mosque, should be the temple for our most cherished human hopes. In other words, I think that neither nation, race, religion, or culture should trump the human universal of reason in the human psyche. And wherever they do, they are the enemies of human progress.
Reason is the universal human grammar on which a hopeful future depends. Of course, there are other things that are universally shared, but reason is chief among them. No form of provincialism should trump reason.
I would offer dogs as an analogy. Dogs have “dog universals”: all dogs—large or small, long hair or short—like to fetch balls, bark at strangers, wag their tails, live in groups, and eat people food dropped from the kitchen table.
Likewise, the human being’s most fundamental characteristic is that she reasons.