The paper sees the core of Hrušovský’s philosophical legacy in his contribution to the philosophy of being. Its central category is co called plain being or being as such. According to the author plain being refers to timeless being. In author’s terminology the latter is perichrony, connecting the synchrony with the diachrony. The doctrine of perichrony is perichronosophy. Folloving Hrušovský, it identifies several perichronical entities or processes, i.e. perichronemas. The author’s perichronosophical interpretation draws upon Filkorn’s exposition of some of the perichronemas in the form of the explicit perichronosophemas, whose identification would be impossible without Hrušovský’s philosophy of the plain (timeless) being. Further aim of the paper is to show, that Hrušovský is rightfully considered to be the Founding father of Bratislava philosophical-methodological school.