Being-alone is a deficient mode of being-with; its possibility is a proof for the latter.
Martin HeideggerTeaching is more difficult than learning because what teaching calls for is this: to let learn. The real teacher, in fact, lets nothing else be learned than learning. His conduct, therefore, often produces the impression that we properly learn nothing from him, if by "learning" we now suddenly understand merely the procurement of useful information.
Martin HeideggerSince time itself is not movement, it must somehow have to do with movement.Time is initially encountered in those entities which are changeable, change is in time. How is time exhibited in this way of encountering it, namely, as that within which things change? Does it here give itself as itself in what it is? Can an axplacation of time starts here guarantee that time will thereby provide as it were the fundamental phenomena that determine it in its own being?
Martin Heidegger