I was having a discussion with a friend recently (who is an advocate of strongly typed languages). He made the comment:
The inventors of Lambda Calculus always intended it to be typed.
Now we can see that Church was associated with the Simply Typed Lambda Calculus. Indeed, it seems he explained the Simply Typed Lambda Calculus in order to reduce misunderstanding about the Lambda Calculus.
Now when John McCarthy created Lisp - he based it on the Lambda Calculus. This is by his own admission when he published "Recursive functions of symbolic expressions and their computation by machine, Part I". You can read it here.
There is some discussion of the relationship between Lisp and Lambda Calculus here, but they don't really get to the bottom of why McCarthy chose to leave it untyped.
My question is - If McCarthy admits he knew about Lambda Calculus - why did he ignore the Typed Lambda calculus? (ie - is it truly obvious that Lambda Calculus was intended to be typed? It doesn't seem that way)