Sartre realized that Husserl’s phenomenology has the potential of bringing immense freedom to the mind. If we are nothing more than what we think about, then no pre-defined inner nature can hold us back. He decided to make Husserl’s phenomenology a key element of his existentialist thought. While he was still in Berlin, Sartre started working on an essay in which he gave an existentialist twist to phenomenology. The essay was published in 1939, under the title, “Intentionality: A Fundamental Idea of Husserl’s Phenomenology.”
Here’s an excerpt from Sartre’s essay:
Consciousness and the world are given at one stroke: essentially external to consciousness, the world is nevertheless essentially relative to consciousness. Husserl sees consciousness as an irreducible fact that no physical image can account for. Except perhaps the quick, obscure image of a burst. To know is to “burst toward,” to tear oneself out of the moist gastric intimacy, veering out there beyond oneself, out there near the tree and yet beyond it, for the tree escapes me and repulses me, and I can no more lose myself in the tree than it can dissolve itself in me. I am beyond it; it is beyond me.
Do you recognize in this description your own circumstances and your own impression? You certainly knew that the tree was not you, that you could not make it enter your dark stomach and that knowledge could not, without dishonesty, be compared to possession. All at once consciousness is purified, it is clear as a strong wind. There is nothing in it but a movement of fleeing itself, a sliding beyond itself. If, impossible though it may be, you could enter “into” a consciousness, you would be seized by a whirlwind and thrown back outside, in the thick of the dust, near the tree, for consciousness has no “inside.” Precisely this being-beyond-itself, this absolute flight, this refusal to be a substance is what makes it be a consciousness. Imagine for a moment a connected series of bursts that tear us out of ourselves, that do not even allow to an “ourselves” the leisure of composing ourselves behind them, but that instead throw us beyond them into the dry dust of the world, on to the plain earth, amidst things. Imagine us thus rejected and abandoned by our own nature in an indifferent, hostile, and restive world — you will then grasp the profound meaning of the discovery that Husserl expresses in his famous phrase, “All consciousness is consciousness of something.”According to Sartre, if we close our mind and somehow stop experiencing, imagining or speculating anything then we will cease to exist. The mind cannot exist by itself—only by living in the world and partaking of all the sensations and experiences that the world has to offer that we become conscious of our consciousness of the world.