Is the self all that can be known to exist?

[Edwardo Piet]

Being-In-The-World is a little more extreme:

Being-in-the-world is Heidegger's replacement for terms such as subject, object, consciousness, and world. For him, the split of things into subject/object, as we find in the Western tradition and even in our language, must be overcome, as is indicated by the root structure of Husserl and Brentano's concept of intentionality, i.e., that all consciousness is consciousness of something, that there is no consciousness, as such, cut off from an object (be it the matter of a thought or of a perception). Nor are there objects without some consciousness beholding or being involved with them.

The part I bolded I disagree with. The rest I agree with.

https://en.wikipedia.org/wiki/Heideggerian_terminology