One of the central arguments for a level-ordering of English morphology (Siegel 1974) is based on the nonoccurrence of certain pairs of affixes, eg*-ness-ic,*-er-ian, etc. The descriptive claim which has been made on the basis of this is that English affixes are divided into two sets, sometimes called LEVEL 1 AFFIXES and LEVEL 2 AFFIXES, and that level 1 affixes are not able to attach to a word to which a level 2 affix has already attached. This has been incorporated into Lexical Phonology/Morphology by having a word pass through a sequence of levels of representation as it is derived. Level 1 suffixes are first attached to the word, with each suffixation followed by the application of a subset of the English phonological rules, eg the English Stress Rule (Halle and Mohanan 1985); then level 2 suffixes are attached to the word, and other phonological rules are allowed to apply. This system encodes not only the ordering of suffixes, preventing level 1 suffixes from attaching to a word to which a level 2 suffix has attached, but also accounts for the fact that certain phonological rules (such as the English Stress Rule) do not take as their input words derived with level 2 suffixes. In fact, this is usually taken as the test of a level 2 as opposed to a level 1 suffix. The English data provide two well-known types of counterexample, which suggest that the generalisation about nonoccurring affix-pairs (from which the level-ordering theory draws much support) may be incorrect. On the one hand, there are BRACKETING PARADOXES, where a level 1 suffix appears to attach to the output of a level 2 prefixation; an example is un-grammatical-ity (where level 1-ity must attach after level 2 un-in order to satisfy categorial selectional restrictions). On the other hand, there are a few specific pairs of suffixes which involve a level 2 suffix preceding a level 1 suffix; for example-abil-ity,-ist-ic,-ment-al. These problems have sometimes been accommodated within systems which nevertheless retain level-ordering for the morphology. For example, Strauss (1982) suggests that suffixes and prefixes are not levelordered with respect to each other (thus dealing with the bracketing paradoxes).