The time domain version of the optical theorem is discussed. The theorem is derived from the optical theorem in the frequency domain by the Parseval's relation. It expresses the sum of the scattered and absorbed energies in terms of the scattered farfield in the forward direction. From the theorem, causality, and reciprocity, a number of results concerning the scattered and absorbed energies from a plane pulse that is scattered from bounded objects are obtained. Some of these results are verified by numerical calculations.