Children acquire natural languages. How they are capable of doing so is mysterious. A child appears to go from learning a few words and sentences to knowing how to construct infinite sentences in her learned language. Such a mystery provoked a long-lasting debate between empiricists and nativists.
Empiricists about language acquisition hold that there is no innate knowledge ‘in the mind’ of a language learner without which the learner could not acquire a natural language. Nativists, by contrast, hold that there must be some innate feature of human minds (beyond the mere dispositional power to learn) that makes language acquisition possible for human beings
In order to explain the phenomena of human language acquisition, one must show how a theory can answer a number of questions. Here are four:
(i) How is it that human beings acquire knowledge from a limited set of experiences? If it turns out that the set of experiences are insufficient to explain the resultant knowledge, then one must look beyond experience. But to what should one turn? If only experiences are sufficient, then what are we to ‘say’ about entities we do not experience (theoretical entities, abstract objects etc.)
(ii) How does one’s theory explain the normativity of a linguistic theory? Grammars of natural languages assume some sort of rule-based, objective feature of an underlying linguistic theory. But, on naturalism, what is the explanation for normativity itself and, more importantly, the universal human ability to recognize it?
(iii) How is it that human beings can acquire concepts from utterances and inscriptions? Do concepts come with the package or must they already be in the mind? If they are already in the mind, how did they get there and what makes us think we can trust them?
(iv) If beliefs or concepts are innate in the human mind, what justifies our beliefs that they are true? Just because we can’t help believing something, this does not entail that it is a justified belief (at least, if naturalism is assumed). Moreover, if naturalism is true, then how do we explain the apparent similarity of concepts between minds?
If one holds to naturalism, one must provide an explanation solely in terms of a naturalistic scientific theory. But naturalism fails on all counts. If one takes an empiricist position, the main problem is with meanings of words and justification of beliefs in entities that evade direct experience. An argument of this kind might run along the following lines:
(1) Language can produce infinite sentences and we can understand them (generative thesis)
(2) Either language is innate or there is some basic vocabulary from which all the rest of language is built up.
(3) If empiricism is true, then language is not innate.
(4) Therefore, there is a finite stock of basic words which together with rules of composition enable us to produce and understand an infinite number of sentences.
(5) The basic stock is the set of names of sensory experiences and names for everyday objects.
(6) If the basic stock is the set of names of sensory experiences and names for everyday objects, then “every word with a meaning in our language must ultimately have a definition in terms of words that name sensory properties and everyday objects.” (Rosenburg, 144).
(7) However, not every word with meaning in our language can ultimately have a definition in terms of words that name sensory properties and everyday objects. (a. Theoretical Terms; b. Moral Facts; c. Mental entities; d. Abstract Entities/Concepts; e. Spiritual Beings (God, angels))
(8) Therefore, Empiricism is false
Empiricists generally either embrace a form of reductive scientism whereby operational definitions are provided for every theoretical term (an acid is what makes blue litmus paper turn red), or they propose a form of anti-realism.
If one takes a nativist position, one must show that if we can acquire languages, then we must already know something. For example, Jerry Fodor argues that language presupposes language: “you cannot learn a language whose terms express semantic properties not expressed by the terms of some language you are already able to use.” (Jerry Fodor, The Language of Thought, 62). Here is Fodor’s argument:
“Learning a language (including, of course, a first language) involves learning what the predicates of the language mean. Learning what the predicates of a language mean involves learning a determination of the extension of these predicates. Learning a determination of the extension of the predicates involves learning that they fall under certain rules (i.e., truth rules). But one cannot learn that P falls under R unless one has a language in which P and R can be represented. So one cannot learn a language unless one has a language.”(Fodor, 64).
Roughly, his argument can be stated as follows:
(1) If S learns a language, L, then S must learn a rule, R, for L
(2) If S learns a rule for L, then S can represent R
(3) If S can represent R, then S already knows a language
(4) Therefore, If S learns a language, S already knows a language
Fodor’s solution is to posit a language of thought, an innate mentalese. If what is required for thinking is a symbolic system that can capture semantic properties and a mechanistic physical base, then we have a powerful option for a naturalist understanding of the mind and language.
However, the account fails to show how sentences in the language of thought can carry any semantic content. Furthermore, Plantinga argues that what we believe—propositions—cannot be concrete and that if they are not concrete, then they are not in languages of thought, at least not in languages of thought that are physically realized.
Both naturalistic empirical and nativist accounts of language fail to account for language acquisition. Theism can explain language acquisition in the first humans. Linguist, Marla Bevin, argues that human beings have language capabilities in virtue of being made in the image of God:
“That language precedes creation is an important point: Language was not created and did not evolve from animal grunts or mews. God eternally has language as part of His rationality. Human beings have language because it is part of the image of God. Thus, God’s use of language is an exemplar for human use of language, and it can be used to provide information about human language” (Marla Perkins Bevin, “Linguistics and the Bible” The Trinity Review No 262).
If one is a nativist, then one ought to embrace theism. On theism, sentences express propositions either because objects of thought are abstract objects or concepts in the mind of God. If one is an empiricist, then one also ought to embrace theism. On theism, God communicates to human beings enabling them to gain concepts of God, angels, moral facts.