The Positive Sciences of the Ancient Hindus c5.s1.8

c5.s1.8

Single particles, then, may have a serial motion. When particles (अवयवाः) combine to form a body (अवयवी), they may move continuously in a straight line, in which case the body is said to move in that direction (अवयविक्रियाया यावदवयवक्रियानिबन्धनत्वात्, the action of a composite whole is determined by the action of the constituent parts taken together). But different particles may move in different directions, or again, the particles may have a curvilinear motion, and in such cases it appears as if different motions are impressed on the body, *e.g.* the falling leaf driven by the wind may have a rotatory or vibratory motion (भ्रमण, स्पन्दन) and a vertical downward motion (पतन) at the same time. Here each particle of the leaf taken separately has only one motion or change of place at the same moment, but from the point of view of the observer द्रष्टा, the particles have a rotatory or vibratory motion in one relation, and the leaf as a whole has a downward motion in another relation. The motion at any instant is really one, but for convenience of analysis we consider the rotatory change of place as separate from the change of place in the downward direction. एकस्मिन् कर्मणि युगपत् द्रष्टृणां भ्रमणपतनप्रवेषनप्रत्यया: कथं भवन्ति । अत्र ब्रूम अवयवावयविनो दिग्विश्लिष्टसंयोगविभागानां भेदात्—*Ibid.*