When they moved to Tasmania, Harwood received from her husband a philosophical treatise work, Austrian philosopher Ludwig Wittgenstein's Tractatus Logico-Philosophicus. Written during World War I and translated into English in 1922, the work attempts to clarify the connection between words and the reality that they ostensibly refer to. The treatise's concise form contains numbered and prioritized declarative statements rather than arguments. It has since become one of the most important philosophical works of the 20th century.

Wittgenstein's writing influenced the content and imagery of Harwood’s poems in several ways. The section on the picture theory of language, or the picture theory of meaning, stands out as a potential influence on Harwood’s writing, particularly the moment between the woman and her former love in “In the Park.” Wittgenstein's theory refers to the wide gap between verbal and nonverbal modes of expression and the importance of statements connecting to real-world images. In Harwood's poem, we see that the surface conversation between the man and the woman bears little resemblance to the reality of their emotional states; what they say is ruled by social expectations and convention, while they are unable to express what they really mean and feel.

Additionally, Wittgenstein was interested in the truth conditions of language, or the conditions under which a sentence could be true—even if these conditions are not necessarily the current reality.