The phrase "contrary instincts" is actually a quote from Virginia Woolf's text, A Room of One's Own, in which she argues that a woman in sixteenth century England would have found it impossible to write poetry due to the pressures against her. By looking at various black Afro-Caribbean female authors who managed to write poetry in the eighteenth century whilst being slaves, Walker identifies a number of parallels between the kind of situation Woolf talks about and the situation that her own ancestors survived. Walker takes the example of Phillis Wheatley, a slave, to explore how important "contrary instincts" are for such individuals who not only managed to write and gain a readership for their work as females, but also as black slaves. Note how Walker describes the "contrary instincts" that Phillis Wheatley endured:
We know that you were not an idiot or a traitor; only a sickly little black girl, snatched from your home and country and made a slave; a woman who still struggled to sing the song that was your gift, although in a land of barbarians who praised you for your bewildered tongue.
"Contrary instincts" therefore refers to the incredibly complex and confusing situation that female writers find themselves in as feeling an all-consuming desire to write but finding themselves in a context where everything seems to oppose that instinct. This is of course, as Walker establishes, made even more apparent by the situation of black female slaves such as Phillis Wheatley, who have so many issues to process and cope with, such as their identity and confusion about "home."