Perhaps the most important connection between phenomenology and existentialism is the philosopher’s role. For the philosopher, the act of philosophizing is not a mere intellectual exercise that could exist solely in consciousness. To the contrary, philosophy is a procedure and inquiry to the self, a “discovery and self-liberation.” The intellectual and cognitive acts of philosophy are participatory in their inquiry of the world. This would be very similar to the understanding that Socrates is the philosopher. He not only taught and philosophized, but he understood that the very act of philosophizing was an act of engagement with the world and it was a way of life. For the existentialist, there are more than thinking and thought experiments to philosophizing. Philosophy is the very demonstration of participation.
To bridge the connection the philosopher must deny the phenomenologist’s transcendental ego. When the philosopher denies the primacy of spectatorial knowledge he becomes an existentialist. This is, perhaps, just as important as understanding the philosopher’s practical role because this provides an initial premise for participation in the world. The existence of the philosopher, or human being, is more than a passive role of non-engagement. A human being can and does engage and can be consumed in participating in and being a part of the world.
Heidegger’s zuhanden understanding of at-hand or ready-to-hand objects is certainly understandable, though his move to vorhanden justified, it must be qualified. That we do not first encounter things and then describe or interpret them as a [zuhanden] are true, especially in light of the Lebenswelt. An understanding of vorhanden and Lebenswelt are contingent upon each other. However, it would not necessarily follow that everything zuhanden is accomplished in a Verweisung manner. Agreed, all things may be used for anything it is not the case that everything has an “in-order-to” [only] function. The world as we first encounter it is intelligible only in relation to human concerns. Of course it would be the case that anything which would be intelligible would have to be related to human concerns; what would follow its negation? However, it is not the case that the relation of human beings to the world is not what determines the world’s intelligibility. This would be concurrent with knowing the world as it is. A world of intelligibility is not necessarily predicated by human intelligibility. The world as it is would be a gigantic referential totality, each of whose constituents relates to others in a “sign-like” way. If the world as it is is composed of zuhanden objects it would be the case that there would be a sign to a referent, or spectatorial vorhanden. The crucial distinction is to recognize that not everything is merely vorhanden and that not everything is zuhanden. It seems to be the case that a referential Lebenswelt must be necessary for zuhanden to be coherent, and necessarily following a detached spectatorial epistemology would be the vorhanden.
 On the converse, the philosopher will also find himself apart from the world in an alienated sense to be discussed.