I think paulokes is suggesting the same thing as I did above. I tried (many times and in more ways I could count) to substitute the intimacy that's only really possible between human beings with philosophical, spiritual, and other so called "higher order" pursuits... intellectual things... never been successful for me. Rather, it is what can create a hole in my soul that I keep expanding by looking to fulfill different needs in the wrong places. I think that there are human needs that can only really be satisfied in their appropriate domains and trying to substitute ("filling the void") with something very different is not going to be successful in many, if not most, cases. Maslow's Pyramid comes to mind... I have always loved that concept as, for me, it describes beautifully the different levels of human needs and how there is a certain hierarchy between them, i.e. we do need to have some basic things fulfilled in meaningful ways in order to even be able to begin exploring the next level. I don't think about the hierarchy as absolute and true in a rigid way, but some of it definitely. For example, whenever I tried to aim for more abstract and "higher" pursuits, or even just meaningful intimacy, but at the same time I had big holes on some basic survival and security needs, it's no more than a house of cards that can be extremely vulnerable and even collapse with every little interference. One of my biggest mistakes earlier in life, I think, was to always aim for the higher domains of existence without caring much about the basics. A lesson learned really in the hard way for me. Also, I think we very often tend to deny some of our basic needs and push it away from consciousness -- then they easily come back as some kind of seemingly mysterious, obscure lack or void in our lives that we desperately want to fill with projections and things that do not really fit, or erase somehow.
But back to relationships, many different versions of interpersonal closeness, vulnerability and a very enjoyable state of being together and exploring life and ourselves (what intimacy mostly entails for me) is possible to find in different kinds of relationships. Platonic friendships, mentor-mentee relationships, I would say I have that quality even with one of my therapists. Each and every relationship is different and can fulfill unique needs. I think that hoping and trying to find "everything" in one package is little more but a romantic illusion and also a potentially quite destructive construct.
I also very much agree with Scott and Berrybean that it may be beneficial to explore the true nature of that need and void you speak of. Of course we cannot easily guess and interpret from a distance what it might be for you, I believe these things are highly personal and only truly make sense in the context of your own personality, history, aspirations etc.