Truthlikeness and Truth Approximation

When Karl Popper published in 1963 in Chapter 10 of Conjectures and Refutations his definition of ‘closer to the truth’ this was an important intellectual event, but not a shocking one. Everybody could react by saying that the definition was as it should be, and even that it could have been expected. For plausible the definition was indeed: a theory is closer to the truth than another if the true consequences of the first include those of the second and the false consequences of the second include those of the first.