Catholic personalism: While she never uses the term "personalism" in her autobiography, Day's Catholic Worker vision (and Peter Maurin's) is animated by Catholic personalism. Catholic personalism, based on a revival of medieval theologian Thomas Aquinas's idea of personhood, gained traction in the early decades of the twentieth century. It was seen as counterweight to fast-growing mass movements, such as communism and fascism, that tended to subordinate the needs of the individual human to the objectives of the "revolution" or the "nation."

In contrast, Catholic personalism stressed the unique personhood of every human as a child of God. In this theology human beings have innate dignity and can not be used as mere "things." Humans are not things because they are part spirit and made in God's image. The proper stance toward other human beings is to treat them with love and respect, as beings both material and spiritual. In Catholic personalism, both body and soul must be attended to.

While Day does not use the word, personalism shows up in the book. For instance, while the Catholic Worker house in New York attracted a large number of prominent visitors, she makes a point of noting a visit from Jacques Maritain, a major proponent of Catholic personalism. Further, the vision Day and Maurin adopted of "work not wages," derives from personalism. While modern capitalism might see humans as entirely material beings and might want to reduce them to productive units earning wages, the "work not wages" movement advocated for attending to the dignity of the whole person, body and spirit. A person would do meaningful work and receive in return the necessities of life, including a community to live in. Day and Maurin's Catholic Worker farms, which she writes about in the autobiography, were an attempt to realize that ideal.

Day's writing style: Influenced by her background as a communist and, especially, her time as a journalist for communist newspapers, Day made a point to write in a plain, accessible style, using ordinary words and images. Her object was always to connect with working people, and, though well-read and educated, she went to pains not to use elite images or allusions. This makes her writing, like George Orwell's, easily accessible to the common reader.