What do you do when you like someone but he doesn't want a relationship even though he likes you too?

I would respect him for his self-awareness and honesty. I would then decide if I can live, even temporarily, with what he's willing to offer. What I would NOT do is go out on an emotional limb, thinking I can change his mind in time. And I would fully accept that any pain caused me by further involvement with him is mine and I own it. He told me the truth.