Loaded sentences

Then Pinker turns to "Linguistic Determinism," a.k.a. the Sapir-Whorf hypothesis, according to which one's native language constrains one's thoughts. Pinker spells out several versions of this idea and provides insightful arguments against them, though he admits that a weak version might have some validity. He concludes that these three rival theories of words' relation to thought undermine one another circularly and that his own theory of a language of thought, which he dubs "conceptual semantics," sits unscathed at the center of this unhappy circle.

The climax of a chapter about space, time and causality in language and thought is a set of eight diagrams showing how "agonists" (entities to which human minds unconsciously attribute a tendency either to move or to stay put) are affected by "antagonists" (agents that exert force on the agonists). If an antagonist's force is great enough, it counters the agonist's tendency to do its thing; otherwise, the agonist successfully resists the force. Also, an antagonist can start or stop acting, thereby altering the agonist's state of motion or rest. The diagrams sum up a whole theory of how human minds conceive of motion and its causes.

This theory, devised by linguist Len Talmy and called "force dynamics," is a key element of Pinker's language of thought as well as a kind of intuitive physics resembling the Aristotelian view of motion, in which objects have intrinsic desires to be certain places; however, it conflicts seriously with the laws of physics as we know them now. Pinker sees this "irrational" aspect of human thought as central to how the mind works. He claims that our concepts of substance, space, time and causality are "digital where the world is analogue, austere and schematic where the world is rich and textured, vague even when we crave precision. . . "