A good programming language should, like oil paint, make it easy to change your mind.
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Paintings usually begin with a sketch. Gradually the details get filled in. But it is not merely a process of filling in. Sometimes the original plans turn out to be mistaken. Countless paintings, when you look at them in x-rays, turn out to have limbs that have been moved or facial features that have been readjusted.
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So the test of a language is not simply how clean the finished program looks in it, but how clean the path to the finished program was.
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What made oil paint so exciting, when it first became popular in the fifteenth century, was that you could make the finished work from the prototype. You could make a preliminary drawing if you wanted to, but you weren't held to it; you could work out all the details, and even make major changes as you finished the painting. You can do this with software too. A prototype doesn't have to be just a model; you can refine it into the finished product....it's good for morale.
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Building something by gradually refining a prototype is good for morale because it keeps you engaged. In software, my rule is: always have working code. If you're writing something you'll be able to test in an hour, you have the prospect of an immediate reward to motivate you.
-- Paul Graham, "Hackers and Painters"