John and Ken begin by asking which comes first--language or thought? For a long time it seemed like thought obviously came first, but more recent philosophy suggests that language molds our thought more than previously considered. Ken points out that you can have a thought and then express it in language, but also that your language creates the world for you and determines the way you think. Ken argues that the categories of language allow us to interpret the world, while John thinks that differentiating between categories of objects is a much easier task and evolves far before language does. Is there any way to tease apart this chicken or the egg problem?

John and Ken introduce Lera Boroditsky, Professor of Cognitive Psychology at Stanford University. John Perry asks Lera to explain the Sapir-Whorf hypothesis mentioned earlier--is language a straight-jacket for thought? Lera describes how the connection between language and thought was first noticed because different languages described the world in very different ways structurally. She describes how different languages use different genders, tense, and case, and how this may alter the way speakers of said language view the world--mainly that in languages that use different genders or tenses or cases, these differences must be noticed in the real world in order to be applied.

John points out that just because, say in Indonesian, there is no past tense, that does not mean that Indonesians have no sense of time. Lera agrees that language is sparse, and describes the opposite of the Sapir-Whorf position which claims that everyone notices the same things about the world, regardless of language. Ken asks for some stronger and weaker alternatives to these disparate camps, and Lera  describes how some of these theories can be altered to be more reasonable and experimentally validated.

John, Ken, and Lera discuss the concept that certain things are just untranslatable between languages, and even two individuals who speak the same language! Lera uses positions in sports to illustrate these differences. Lera discusses experimental evidence for and against the Sapir-Whorf hypothesis with callers who relate their own personal losses in translation and theories of language and thought.

• Roving Philosophical Report (Seek to 3:54): Polly Stryker interviews Linda, who is trying to resurrect a dying native american language that is part of her heritage. This ancient language reveals how close her tribe once was to nature, and may indicate how one's language can transform one's perception of the world.

• 60-Second Philosopher (Seek to 49:29): Ian Schoales discusses the development of the Sapir-Whorf hypothesis and Chomsky's universal grammar--at lightning speed!