Democritus adopted the atomical doctrine as new modelled ; and, by the help of a little more ingenuity, extended its reputation, without cor recting any of its absurdities. Both these philoso phers had retained the gods in their systems, from a regard to their own safety, and in compliance with popular prejudices. But Protagoras, a little bolder, and a little honester, than his predecessors, hesita ted not to speak freely on the subject, to deduce from the doctrine its legitimate consequences, and thus fairly to explode the gods from the universe. For this, instance of his zeal, he was banished from Athens ; and may claim the honour of being the protomartyr of atheism.
At length appeared Epicurus, who so far outdid the labours of all who had gone before him, in en 2 larging and enforcing the atomical doctrine, that his • warm admirer Lucretius claims for him the honour of the whole invention. The poet appears particu larly grateful for the emancipation of the human mind from the influence of religion, which was completely effected according to the system of his master : Humana ante °cubs fretie cum vita jacere: In terris opp•essii gravi sub religione, Primurn Grains homo snort ales tollere contra Est oculos ausus.
Epicurus adapted the doctrines of the ancient ato mists, to explain the organization and qualities of bo dies ; and in so far as he adheres to their principles, he advances many ingenious things in his speculations. But he deserts the paths of true science, and of sober thinking, wheff he attempts to account for the pro duction of all things without the operation of an in telligent cause. According to him, atoms are the elements, from which all things are compounded, and into which they are ultimately resolved. Not only are they the materials, out of which bodies are made; but that energy or principle of motion, which essen tially belongs to them, is the sole agent in all the ope rations of nature. Having assumed this principle, he then proceeds to show, that all the changes in the figure and properties of bodies consist in local motion. Heat is the influx of certain small, round corpuscles, which insinuate themselves into the pores of bodies in continual succession, till by their perpetual action, the parts are separated, and at length the body dis solved. Cold is the influx of certain irregular atoms, whose motion is slower than those which occasion heat. Production and dissolution are nothing more than a change of the position of atoms, or an increase or.di minution of the particles of which bodies are com posed.
But the original formation of the world is the prin cipal thing to be accounted for ; and this Epicurus, with most other cosmogonists, makes a very easy pro cess. Accordingly he tells us, without any hesita
tion, and without the semblance of proof, that a finite number of atoms, tumbling through,the vacuum, were, in consequence of their innate motion, collected into one indigested mass. A small difficulty, however, occurs here ; if these atoms fell perpendicularly, how did they ever happen to unite ? They could not over take each other : for in a vacuum all bodies fall with equal velocity, whatever may be the difference of their specific gravity in other circumstances. The same objection holds, supposing them to fall obliquely : neither will it do to say that they fell tumultuously, in all different directions : because the principle of gravity, with which they are supposed to be endued, must act uniformly ; and if there be any deflection of the atoms from one regular course, it must proceed from some external cause, which is altogether con trary to Epicurus's system, which ascribes every thing to the energy and activity of atoms. These difficul ties were not unobserved ; but they were easily ob viated, so lung as hypothesis could be substituted for argument. Accordingly, an expedient was devised, to remove these objections : and it W.aS asserted, that the atoms suffered a slight deflection in their course, at different times and different places, by which means they effected a junction. At the same time, this de- I flection was so small, as not to constitute obliquity ; for Lucretius loudly protests against such heresy as this, and declares it to be contrary to common sense, that bodies should descend by their own weight, in an oblique direction. Nevertheless, to answer his pin- pose, he is forced to assign to the atoms a declination from the perpendicular descent, whilst he denies that this declination can constitute oblique motion. They may understand this who can. This, however, is a favourite mode of -solving difficulties with Epicurus. For, when talking of the form of the gods (another knotty subject) he maintains that they have non cor pus, sedquasi corpus ; non sanguinenz, sed quasi san guinem, de nat. Deor. 1. i. ); so with regard to the primordial atoms, he seems to say, that they have non. elinanzen, sed quasi clinanien. With respect to these mysteries, we can for once cordially adopt the senti ments of an Epicurean ; here et inventa sent acutius, et dicta subtilius ab Epiczzro, quanz zzt quivis ea possit agnoscere.