The opening stanza of Aphra Behn's poem "On Loving Two Equally" reads as follows:
HOW strongly does my passion flow,
Divided equally 'twixt two?
Damon had ne'er subdued my heart,
Had not Alexis took his part;
Nor could Alexis powerful prove,
Without my Damon's aid, to gain my love.
What, exactly, do these lines mean or imply? Several possibilities present themselves.
The two key lines in trying to decipher the meaning of this stanza would seem to be lines 4 and 6. What, exactly, does the speaker mean when she says that "Alexis took [Damon's] part"? One might read this phrase as suggesting that Alexis praised Damon in an effort to encourage the speaker to love Damon. One might assume that Alexis and Damon are friends and that Alexis was acting on his friend's behalf or in his friend's interests. One might come to a similar interpretation of line 6, only this time with Damon acting on behalf of Alexis. However, by the time one reaches line 6, such a situation seems implausible, and the rest of the poem does not support such an interpretation.
For this reason, "took his part" in line 4 probably means that Alexis "stood in for" Damon or "was present when Damon was not present." A similar kind of meaning can then be derived from line 6 (although less clearly there).
All in all, the opening stanza seems to suggest that the speaker is divided in her affections. She feels passionate toward Damon when in the presence of Damon, and she feels passionate about Alexis when she is in the presence of Alexis. When the two are present together (she later admits) she is hopelessly confused.
The irony, of course, is that such "passion" is not true "love." Passion during this period was considered irrational; love was supposed to be rooted in genuine affection and in wise judgment. The speaker seems to be displaying neither of these traits. She seems preoccupied only with the physical attractions of Damon and Alexis. Thus, one might argue that by claiming to "love" both of them equally, she reveals that in fact she feels genuine, true love for neither of them. Instead, she feels only mere passion and physical attraction.
Such, at least, is an ironic reading of this stanza -- a reading the rest of the poem supports.