I find the use of the word "inspecific" very natural. It makes sense and flows easily in sentences I speak and write (to myself at least). However, upon inspection, it is apparently not a valid English word, instead being nonspecific (A.H.D. 5), unspecific (O.D.O.) or something of that sort.
We use the in- prefix to negate the primary meanings of words very often, for instance in the words "inadequate" and "invariable". I feel like ignoring all of the signs telling me to use "non-specific" instead of "inspecific" and go with what I find right. What about you? Do you find the word "inspecific" right or wrong? Why can't we negate it, like we negate many other words, simply through prefixing an in-?
Also, as a rule of thumb, Latin words usually seem to take the in- prefix when negated, whereas Germanic words seem to take the un- suffix. Variable, adequate and specific have Latin origins according to The Online Etymology Dictionary. Why does specific, a Latin derived word, seem to be an exception?