Above all else, the mentat must be a generalist, not a specialist. It is wise
to have decisions of great moment monitored by generalists. Experts and
specialists lead you quickly into chaos. They are a source of useless nit
picking, the ferocious quibble over a comma. The mentat-generalist, on the
other hand, should bring to decision-making a healthy common sense. He must not
cut himself off from the broad sweep of what is happening in his universe. He
must remain capable of saying: "There's no real mystery about this at the
moment. This is what we want now. It may prove wrong later, but we'll correct
that when we come to it." The mentat-generalist must understand that anything
which we can identify as our universe is merely part of larger phenomena. But
the expert looks backward; he looks into the narrow standards of his own
specialty. The generalist looks outward; he looks for living principles,
knowing full well that such principles change, that they develop. It is to the
characteristics of change itself that the mentat-generalist must look. There
can be no permanent catalogue of such change, no handbook or manual. You must
look at it with as few preconceptions as possible, asking yourself: "Now what
is this thing doing?"

-The Mentat Handbook