Abstract
This paper makes an effort to interpret the relationship between the concepts "Zuhandenheit" (readiness-to-hand) and "Vorhandenheit" (presence-at-hand), as they are analysed in §§ 15-16 of Heidegger's "Being and Time".
These concepts are two modes of existence of the beings met in our surrounding world. So, they don't concern different things. Heidegger doesn't give the title "things" to the beings ready-to-hand; he names them "equipments" (Zeug). It's a concept relative to the Aristotelian "organon", which Aristotle exemplifies with the human hand as a primary equipment. But Zuhandenheit isn't a quality of the things; the term has to do with the secret character of the equipments as the maining way of their disclosure. It's the Being-in-itself of the equipments, as long as they are useful. This Being-in-itself has nothing common with the Kantian Ding an sich, which is based on the presupposition of a cognitive relationship between subject and object.
I posit also the question, whether Zuhandenheit can rendet the secretness and familiarity of our immediate approach to the environment, and my answer to this question is negative.