Yes, the pelte shield of the Phalangites had its uses. It wasn't of course as sophisticated as the aspis (not hoplon guys, that's incorrect), but the longer the spear the smaller the shield because for a 5-6m pike you have to be able to use both hands to grip it.

Returning to the aspis debate now, I must say that I too don't think a pilum would be able to easily penetrate a sturdy aspis. I just don't think it's impossible, as Phalanx so vigorously claims.

Maion