SECT.  LXXXIV.  Atoms cannot make any Compound by the Motion the Epicureans assign them.

These atoms of so many odd figures—some round, some crooked, others triangular, &c.—are by their essence obliged always to move in a straight line, without ever deviating or bending to the right or to the left; wherefore they never can hook one another, or make together any compound.  Put, if you please, the sharpest hooks near other hooks of the like make; yet if every one of them never moves otherwise than in a line perfectly straight, they will eternally move one near another, in parallel lines, without being able to join and hook one another.  The two straight lines which are supposed to be parallel, though immediate neighbours, will never cross one another, though carried on ad infinitum; wherefore in all eternity, no hooking, and consequently no compound, can result from that motion of atoms in a direct line.