OOP criticism - what means this Alexander Stepanov's phrase?

Question

On Object Orientation criticism, Alexander Stepanov said:

<< I find OOP technically unsound. It attempts to decompose the world in terms of interfaces that vary on a single type. To deal with the real problems you need multi-sorted algebras — families of interfaces that span multiple types. I find OOP philosophically unsound. It claims that everything is an object. Even if it is true it is not very interesting — saying that everything is an object is saying nothing at all. >>

What means:

"To deal with the real problems you need multi-sorted algebras — families of interfaces that span multiple types."

Answer 1

I think the context is important here.
The quote is from an interview made with Stepanov in 2008.
http://www.stlport.org/resources/StepanovUSA.html

He explains a lot about STL and contrasts it against OOP design.

"Abstraction works! Generic programming assumes that there are some fundamental laws that govern the behavior of software components and that it is possible to design interoperable modules based on these laws. It is also possible to use the laws to guide our software design. STL is an example of generic programming. C++ is a language in which I was able to produce a convincing example."

In my understanding he approaches programming from the perspective of a theoretic mathematician. For him, an algorithm that describes how the world works, is more valuable, than modeling a specific thing as a class and describing its particular capabilities with methods. So the criticism of OOP is that it is not universal enough.

Answer 2

Martin Taylor could you explain the phrase stated below plz?