The feeling of love must develop in all of its details
In order to apprehend God's higher love, one must first develop the feeling of love itself. If the feeling of love is not developed in a person, that person will not be able to apprehend God's higher love.
If one does not develop an aesthetic sense, one will not be able to apprehend divine beauty at a high level.
Secular literature or philosophy
The generation wants to develop itself, to apprehend beauty and love.
A person who does not grow spiritually, who does not read secular literature, cannot develop a sense of the awe or of love, so as to apprehend God's glory at the necessary level. Such as person will perceive God at a low level and will be unable to advance from there. Therefore, the literature and philosophy of one's generation and the desire to comprehend the beauty and richness of the world are necessary components of spiritual development. In other words, in this excerpt Rav Kook presents the radical idea that secular literature is needed not in order - as some religious people believe - to learn how nonreligious people live and how to change their mind, or to acquire techniques for influencing the outside world, but for one's own religious and spiritual development. This is not a matter of "pragmatism," but of the inherent value of literature and art, and their importance to the apprehension of the divine. In this sense, we must note that the Torah and commandments, also, are not ends in themselves, but paths to holiness. Thus, in some sense, secular literature and Torah are part of the same spiritual realm.