It is a fair question for the enquirer who encounters theological talk to ask at what point, and in what way, such talk is rooted in common human experiences that can be discussed. His difficulty is that, while not wanting to deny to theological talk some empirical foundation, he is at a loss to know what this foundation is. The problem is especially acute when there appears to be a claim by believers that only ‘insiders’ can really understand the language that is being used: that is, when credo ut intelligam is interpreted as ‘unless you are prepared to believe what we believe you won't be able to understand what we are talking about’. The enquirer feels that he is being invited to take a blind plunge, on the grounds that only real swimmers can know what swimming is, when he has no idea what it is he is being invited to plunge into, or how to do it.