Assessment and impact: these are the new watchwords in higher education. We have assessment indicators in the social sciences, the physical sciences and our business and law schools, which ask: "What does this research do? What footprint does it leave? Are its benefits worth the costs?"
Alas, the humanities do not respond well to these questions. One might as well ask the business and finance ends of campus what they contribute to the aesthetic richness of our lives - but, oddly, no one ever does.
When the assessors call, we humanists like to talk about "critical thinking", but we do not like specifying what we are critically thinking about. So let me give it a shot.
It has become a truism that the humanities teach us how to understand "difference" in some kind of generally tolerant way. I don't think that is always true: we all seem to wind up with different ways of understanding difference.
But I think the humanities help us come to terms with the possibility that some forms of difference might be unresolvable and that some kinds of conflict might be intractable.
This is one of the critical dilemmas of our time: how to develop and maintain pluralist societies that include people who are not pluralists. Grappling with this conundrum requires extraordinary suppleness of mind, a willingness to think in ways that do not immediately reach for easy resolution, and a commitment to lifelong learning - and that's just for starters.
Here is the problem: we do not know how to measure such things. We do not know how to test people to see if we have enhanced their suppleness of mind or their love of lifelong learning.
We believe that education in the humanities consists of training in how to think and in developing a richer language for thought, but all the instruments agree: we cannot prove it, we cannot show the "value-added" aspects of a humanities education.
We have some wonderful anecdotal evidence, of course. Here is mine: there is no question in my mind that I was better equipped to deal with the birth of a child with Down's syndrome because of my training in the humanities.
I am less inclined to pathologise disability, more willing to entertain the idea that nothing human should be alien to us, more sympathetic to the argument that many disabilities are disabling chiefly because our built environments and social policies make them so. But I am not sure I can quantify that - and I am pretty sure I do not need to.
Perhaps we can merely say that in studying the humanities, people get acquainted with some of the most imaginative and intellectually challenging texts ever written, from Aeschylus' Oresteia to Immanuel Kant's Critique of Judgment to the novels of J.M. Coetzee.
And to the question, "is it useful to get acquainted with imaginative and intellectually challenging texts?", we can probably only answer "maybe" - it depends on whether you think that a life including such texts is better than one without.
We humanists start from the conviction that the examined life is better than the unexamined life, even if it is more difficult and painful. We think that this is all we can offer: an examined life. How can we assess such a thing? What is its impact? It depends. Come back and talk to us again in 50 years.