Personally, I find his prose to be plain and boring but, his insight is really interesting.
"Now we would like to go a step further and extend the system to handle differentiation. This is a favorite problem, and one which has historical significance: in the summer of 1958 John McCarthy decided to investigate differentiation as an interesting symbolic computation problem, which was difficult to express in the primitive programming languages of the day. This investigation led him to see the importance of functional arguments and recursive functions in the field of symbolic computation. For example, McCarthy invented what we now call mapcar to express the idea that the derivative of a sum is the sum of the derivative function applied to each argument. Further work led McCarthy to the publication in October 1958 of MIT AI Lab Memo No. 1: "An Algebraic Language for the Manipulation of Symbolic Expressions," which defined the precursor of Lisp."
PAIP is filled with writing like this. You could remove this paragraph from the book and, it wouldn't make the explanation any more or less comprehensible. The level of detail at which he provides this insight is interesting. It ends up being more than just amusing anecdotes. It's what makes the book worth reading imo.
"Now we would like to go a step further and extend the system to handle differentiation. This is a favorite problem, and one which has historical significance: in the summer of 1958 John McCarthy decided to investigate differentiation as an interesting symbolic computation problem, which was difficult to express in the primitive programming languages of the day. This investigation led him to see the importance of functional arguments and recursive functions in the field of symbolic computation. For example, McCarthy invented what we now call mapcar to express the idea that the derivative of a sum is the sum of the derivative function applied to each argument. Further work led McCarthy to the publication in October 1958 of MIT AI Lab Memo No. 1: "An Algebraic Language for the Manipulation of Symbolic Expressions," which defined the precursor of Lisp."
PAIP is filled with writing like this. You could remove this paragraph from the book and, it wouldn't make the explanation any more or less comprehensible. The level of detail at which he provides this insight is interesting. It ends up being more than just amusing anecdotes. It's what makes the book worth reading imo.