In other words, in the definition we have given of it, is it really possible to add to the boundary between the science of personality and the biological sciences a no less firmly established boundary, on the other side of the terrain thus sketched out, between the science of personality and the social sciences?
1 Answer
... a no less firmly established boundary, - a boundary which is at least as firmly established. It is similar to the Maths "not less than" which is mathematically the same as "greater than or equal to".