Thus, it is Tinbergen’s insight to include the questions of survival value, evo-
lution, and ontogeny, which all pertain directly to genetic programs, but only
indirectly to natural laws, in addition to the question of causation. Therefore,
the four questions in (1) all have dual causation, being controlled primarily
by genetic programs and ultimately by natural laws. (Tinbergen’s questions in
(1) are reordered to match Chomsky’s questions in (2).)
(1) a. causation
b. ontogeny
c. evolution
d. survival value
Turning to biolinguistics, we have seen that it has also developed by extending
the conceptual framework of modern science. In addition, as Chomsky (1980:
185) notes, it has incorporated into its “natural philosophy” a view that it is
possible to “regard the language capacity virtually as we would a physical organ
of the body” and to “investigate the principles of its organization, functioning,
and development in the individual and the species.”
Therefore, it is natural that biolinguistics have basic questions comparable
to those of ethology. Actually Chomsky (1995: 17–18) proposes the following
five questions:
(2) a. What does Jones know when he has a particular language?
b. How did Jones acquire this knowledge?
c. How does Jones put this knowledge to use?
d. How did these properties of the mind/brain evolve in the species?
e. How are these properties realized in mechanisms of the brain?
Boeckx (2010: 23), among others, suggests that Tinbergen’s four q uestions (1)
“correspond point by point to” Chomsky’s fi ve questions (2).^9 When (1) and
(2) are closely examined, however, it turns out that there are three discrepancies
between them. First, Chomsky divides Tinbergen’s fi rst question (1a) causation
into three separate questions, i.e., (2a) what does Jones know? (2c) how does
Jones put this knowledge to use? and (2e) how are these properties realized
in mechanisms of the brain? Second, once (1a) is divided into three questions,
its fi rst part (2a) does not include the notion of causality, as we see when we
discuss the nature of mechanisms in biolinguistics in section 3.2. Third, Tinber-
gen’s question (1d) of survival value is not included in Chomsky’s set of basic
questions (2). Putting aside the third discrepancy, let us consider why there are
these discrepancies between (1) and (2), focusing on the fi rst and the second.
The first and the second discrepancies are related to each other and are the result
of the nature of idealization and abstraction adopted in biolinguistics. Chomsky
(1980: 188) explains the idealization involved in biolinguisti cs as follows:
Continuing to think of the system of grammatical rules as a kind of “men-
tal organ”, interacting with other mental organs with other functions and182 Masanobu Ueda