Note 61 — APPENDIX I On the Meaning of the Word “Activity”

According to this principle, the mere fact that a particle is moving with a certain velocity in a certain direction, is in itself a reason why it should continue to move with the same velocity in the same direction.… Now, in so far as continuance of change in a certain direction is traceable to the pre-existence of change in that direction, this whole process may be regarded as being in a perfectly intelligible sense, self-determining (“Analytic Psychology,” Vol. I, p. 146).