There are certain adjectives which express an ultimate thought and should not be modified further; they are the superlative or uncomparable adjectives. They describe an absolute state so that any effort to add (or subtract) from their meanings results in either a contradiction or a redundancy.
A common illustration: “That diamond is more unique than any other.” The more does nothing to assist in the description of the diamond; if it is unique, by definition it is alone in the world, and there is no other like it.
Thomas Jefferson is said to be the principal author of one of our most famous documents, the Constitution. He receives the highest grades in his practical application of what were then radical political concepts; not so much for his grammar, however. We are all familiar with its preamble, “We the People of the United States, in order to form a more perfect Union . . .” A thing cannot be better than perfect; its quality is absolute and incapable of improvement. What the framers of that glorious document intended probably was to set a goal, to form a more nearly perfect Union in comparison to that which they had rebelled against. By inserting more nearly, the adjective perfect loses its absolute quality.
The following is a list of many of the superlative adjectives:
absolute inevitable singular
adequate infinite stationary
chief irrevocable sufficient
complete main unanimous
devoid manifest unavoidable
entire only unbroken
false paramount uniform
fatal perfect unique
favorite perpetual universal
final possible void
ideal preferable whole
impossible principal
Be alert in using them and avoid the temptation to embellish any of them when you use them to express an absolute concept.
– Ken Butera