  The 4th Concept detector presently being designed for the International
Linear Collider introduces several innovations in order to achieve the
necessary experimental goal of a detecter that is 2-to-10 times better than the
already excellent SLC and LEP detectors. We introduce a dual-readout
calorimeter system, a cluster counting drift chamber, and a second solenoid to
return the magnetic flux without iron. We discuss particle identification,
momentum and energy resolutions, and the machine-detector interface that
together offer the possibility of a very high-performance detector for
e^+e^-physics up to $\sqrt{s} = 1$ TeV.
