This is so incredibly simple to answer I'm just a little surprised that there wasn't a DUmmie able to chime in with a coherent answer.
At it's simplest level the answer is yes.
Again at its simplest level, without capital are you able to provide labor? In other words, if you wanted to be warm (capital) would it be worth it to drag yourself outside to cut wood (labor)?
Could you set up a lemonade stand with out investment (capital), you know, the wood for the stand, the signs, lemons, water. Without capital labor means nothing.
This is just another example, among legion, why DUmmies fail in all things related to economics.