The central theme of the seventh of Rilke's "Letters to a Young Poet" is that to love another is, of necessity, a difficult and demanding undertaking, because it is the most important endeavor of our lives. He warns his young friend against being lured away by "what is easy and toward the easiest side of the easy," advising him to "trust in what is difficult," because everything in nature grows and becomes itself most spontaneously "at all costs and against all opposition."

As a source of difficulty, as almost a spiritual discipline, he recommends solitude. In solitude, he suggests, by first learning about themselves through contemplation and reflection, the young can best learn what it is to love another. As Rilke says, "what would a union be of two people who are unclarified, unfinished, and still incoherent"?

Equally significant, in the pursuit of such a difficult, genuine love, is the idea of avoiding convention. "Whenever people act out of a prematurely fused, muddy communion, every action is conventional," Rilke writes. Questions of love, he says, cannot be resolved by public agreements; "they are questions, intimate questions from one human being to another, which . . . require a new, special, wholly personal answer."

The final idea animating this letter on the demanding nature of love is the importance of women being considered the equal of men, a development whose imminence he envisions: "This advance (at first very much against the will of the outdistanced men) will transform the love experience, which is now filled with error, will change it . . . into a relationship that is meant to be between one human being and another."

The central theme of Rilke's seventh letter is love. Kappus has asked Rilke to give him advice about romantic love. Rilke responds with a philosophical discourse about what love is.

Rilke makes the point that real love is difficult and that what most young people regard as love is mere physical attraction or self-interest. Second, Rilke states that love takes sacrifice, time, and pain, if it is not going to be shallow. Third, love also requires solitude. This may seem counter-intuitive, given that being in love usually means wanting to be with the beloved all the time. However, Rilke says solitude is a necessary ingredient because it teaches self knowledge and helps us to mature. He writes that love “consists in the mutual guarding, bordering and saluting of two solitudes.”

He also tries to redefine womanhood away from stereotyped notions of femininity. Instead, he recasts love as a relationship between two equals, the woman perceived as "something which makes us think of no complement or limitation."

One of the central themes in Rilke's seventh letter is the intrinsically intertwined nature of love and solitude.

First, Rilke tells his young poet friend that while it's normal to want to struggle against solitude and to not feel alone or lonely anymore, one should hang on to one's solitude and listen closely to what it can teach us about ourselves. Rilke writes, "it is good to be solitary, for solitude is difficult; that something is difficult must be a reason the more for us to do it." 

Second, Rilke says that while love and solitude may seem to be opposites, they actually are not. Even though it might seem like being in love with someone is the opposite of solitude, the act of loving someone requires a lot of solitude. This is because loving someone is difficult and requires a lot of growth. Rilke writes, "learning-time is always a long, secluded time, and so loving, for a long while ahead and far on into life, is--solitude, intensified and deepened loneness for him who loves."

Third, Rilke says that if we understand that love and solitude are deeply connected because both require a lot of work and self-reflection, we can better understand love. He tells us that "if we nevertheless hold out and take this love upon us as burden and apprenticeship, instead of losing ourselves in all the light and frivolous play...then a little progress and alleviation will perhaps be perceptible to those who come long after us; that would be much." Thus, if we can approach love as though it requires the same amount of work that solitude does, we can better understand one another and ourselves, and perhaps spread this understanding and love to others.