In her 1946 profile of Jean-Paul Sartre, commissioned by Harper's Bazaar, Beauvoir outlines the basic tenets of his existential philosophy: ‘there are two ways of existing: in the world, one comes across inert things that remain indefinitely equal to what they are [en-soi]; and on the other, men who are consciousnesses and freedoms live in this world [pour-soi]’ (2004: 229). In doing so, Beauvoir explains that existentialism is more than a type or approach of philosophy, rather it is a way of being-in-the-world, a way of life. On the face of it, the article's function was to sell Sartre to the US, speaking to his style of working and thinking, thereby attaching a personality to existential philosophy. Yet, despite Beauvoir appearing to write about Sartre, the brief article also subtly presents the contour of her existential ethics, which was outlined in greater detail the following year in The Ethics of Ambiguity and further elaborated on in specific relation to women's situation in The Second Sex.

Throughout the article, Beauvoir writes of one's fleeing from freedom and argues for the responsibility that freedom requires, implicitly characterising different versions of existence (sub-man, serious man, passionate man), and using the figure of Sartre to illustrate the writer-artist who ‘as a creator of imaginary works’ is able to ‘escape from getting stuck in the paste of contingent life’ (Beauvoir 2004: 231). ‘Jean Paul Sartre: Strictly Personal’, as a description of Sartre as a man, reads as a publicity love letter but, more subtly, it indicates Beauvoir's emerging emphasis on ambiguity as a foundational expression of the personal within ethical decision, appeal and the pursuit of freedom.

Debra Bergoffen has written on Beauvoir's ‘muted voice’, found within the ‘trap’ or frame of Sartre's philosophy, arguing that it speaks to an existential ethics that Sartre did not foreground or craft closely in his work. For Bergoffen, this muted voice identifies emotional experience, inclusive of ‘joy, generosity, the gift, the erotic and the couple’ (1997: 2), as the primary connection between body and consciousness. It expresses an ‘erotic generosity’ which Bergoffen views as the premise of Beauvoir's philosophy: an ethics of existence that juxtaposed the erotic against the patriarchal.