And, just as in pulling down an old house, we usually reserve the ruins to contribute towards the erection, so, in destroying such of my opinions as I judged to be Ill-founded, I made a variety of observations and acquired an amount of experience of which I availed myself in the establishment of more certain.
What conceptual (logical, cognitive) capacities did they acquire when they acquired language?
For, occupied incessantly with the consideration of the limits prescribed to their power by nature, they became so entirely convinced that nothing was at their disposal except their own thoughts, that this conviction was of itself sufficient to prevent their entertaining any desire of other objects; and over their thoughts they acquired a sway so absolute, that they had some ground on this account for esteeming themselves more rich and more powerful, more free and more happy, than other men who, whatever be the favors heaped on them by nature and fortune, if destitute of this philosophy, can never command the realization of all their desires.
Vast domains of human understanding, including the supernatural and sacred, the specifics of folk and formal science, human-specific kinship systems (such as the distinction between cross- and parallel cousins), and formal social roles (such as “justice of the peace” and “treasurer”), can be acquired only with the help of language.
Actually, while Markson and Bloom did argue against a dedicated system for learning words, they did not conclude that words are acquired by a domain-general mechanism.
Such words are not used, and presumably could not be acquired, in isolation from some syntactic context.
And as functional morphemes go, so go verbs, since verbs encode similar kinds of grammatical and semantic information (Gentner, 1981; Pinker, 1989; Talmy, 1985), have similarly close linguistic, psychological, and neurological ties to syntax (Gentner, 1981; Pinker, 1989; Shapiro, Pascual-Leone, Mottaghy, Gangitano, & Caramazza, 2001), and, at least in part, require syntactic analysis to be acquired (Gleitman, 1990; Pinker, 1994a).
This enormous expressive power clearly meshes with two of the other zoologically unusual features of Homo sapiens: a reliance on acquired know-how and a high degree of cooperation among non-kin (Pinker, 1997; Tooby
But given that inner speech depends on having outer speech, acquired in a communicative situation, we are inclined to think that if anything is a by-product (or “spandrel”) here, it is inner speech.
It meshes with other features of human psychology that make our species unusual in the animal kingdom, namely a reliance on acquired technological know-how and extensive cooperation among non-kin.