Is it possible to use synths without hardware?

I have ACID pro 7.0, and I recently downloaded a VST Synth to use in it. Upon doing this I discovered that I have no way of using said synth cause I have no midi hardware. Is it possible to use maybe virtual hardware or some kind of emulator so I can fool the computer into thinking my keyboard has midi capabilities or whatnot, or will I just have to buy a midi keyboard?