Rationalist Arguments

Our knowledge of grammar is innate. Poverty of stimulus argument. Children learn grammar so quickly from such poor information that their knowledge of grammar can't be derived from sense experience. We use incorrect grammar in our everyday speech, often talking in interrupted and incomplete sentences; grammatical mistakes are usually not corrected; children are given too few examples of correct grammar to classify them and apply them to other sentences. So learning grammar does not come from the experience of language. Instead, exposure to language triggers an innate knowledge of grammar.

Criticism

The ability to construct grammatically correct sentences is skill based knowledge rather than propositional knowledge. If it were propositional then children would have innate beliefs about grammar, it is much clearer to say that it is an ability rather than knowledge.

There are certain concepts in life that we are born with innate knowledge of. Nothing in nature is ever perfectly equal, so where did we get the concept of equality from? We can never physically experience beauty by itself, so where did we get the concept of beauty from? These concepts are innate, and we are born with them already in our minds.

Criticism

We can easily form the concept of equality by abstracting information and ideas from what we experience in nature. Nothing in nature is ever perfectly equal because ey all differ in length, but we can work out that things are equal when they differ by no length.

There are many developments in our cognitive capacities that appear to be predetermined. For example a newborn can only see up to 30cm ahead of them, but within a few weeks their eyesight has developed and they can see much further. Caruthers' line of reasoning is that if our capacities can develop, why not concepts and knowledge? At a genetically predetermined point in life, children begin to use an idea that has not been acquired from sense experience. However, the child must be exposed to relevant stimuli in order to Access this knowledge.