Universality of Phonetic Features

Quotes from N. Chomsky and M. Halle  Sound Pattern of English (1968) p. 4.   (freely reformatted)

``General linguistics attempts to develop a theory of natural language as such, a system of hypotheses concerning the essential properties of any human language.  (They are) often referred to as linguistic universals.  The significant linguistic universals are those that must be assumed to be available to the child learning a language as an apriori innate endowment.

That there must be a rich system of apriori properties ... is fairly obvious. ... (since)

It is useful to divide linguistic universals ... into two categories: