the philosopher barry smith writes that brentano's thesis about intentionality has "proved to be one of the most influential in all of contemporary philosophy. it gave rise to husserlian phenomenology, but it also lies at the root of much of the thinking of analytic philosophers on meaning and reference and on the relations of language and mind. in addition, the notion of intentionality, and brentano's use of this notion as a criterion for the demarcation of the psychological realm, pervades much contemporary philosophizing within the realm of cognitive science." scruton commented in 1994 that none of the volumes of "psychology from an empirical standpoint" "fulfil the promise made in the book's title", adding that brentano eventually came to doubt that an empirical science of the mental is likely to be invented.