History of Western Philosophy - Bertrand Russell [43]
As a result of collisions, collections of atoms came to form vortices. The rest proceeded much as in Anaxagoras, but it was an advance to explain the vortices mechanically rather than as due to the action of mind.
It was common in antiquity to reproach the atomists with attributing everything to chance. They were, on the contrary, strict determinists, who believed that everything happens in accordance with natural laws. Democritus explicitly denied that anything can happen by chance.6 Leucippus, though his existence is questioned, is known to have said one thing: 'Naught happens for nothing, but everything from a ground and of necessity.' It is true that he gave no reason why the world should originally have been as it was; this, perhaps, might have been attributed to chance. But when once the world existed, its further development was unalterably fixed by mechanical principles. Aristotle and others reproached him and Democritus for not accounting for the original motion of the atoms, but in this the atomists were more scientific than their critics. Causation must start from something, and wherever it starts no cause can be assigned for the initial datum. The world may be attributed to a Creator, but even then the Creator Himself is unaccounted for. The theory of the atomists, in fact, was more nearly that of modern science than any other theory propounded in antiquity.
The atomists, unlike Socrates, Plato, and Aristotle, sought to explain the world without introducing the notion of purpose or final cause. The 'final cause' of an occurrence is an event in the future for the sake of which the occurrence takes place. In human affairs, this conception is applicable. Why does the baker make bread? Because people will be hungry. Why are railways built? Because people will wish to travel. In such cases, things are explained by the purpose they serve. When we ask 'why?' concerning an event, we may mean either of two things. We may mean: 'What purpose did this event serve?' or we may mean: 'What earlier circumstances caused this event?' The answer to the former question is a teleological explanation, or an explanation by final causes; the answer to the latter question is a mechanistic explanation. I do not see how it could have been known in advance which of these two questions science ought to ask, or whether it ought to ask both. But experience has shown that the mechanistic question leads to scientific knowledge, while the teleological question does not. The atomists asked the mechanistic
question, and gave a mechanistic answer. Their successors, until the Renaissance, were more interested in the teleological question, and thus led science up a blind alley.
In regard to both questions alike, there is a limitation which is often ignored, both in popular thought and in philosophy. Neither question can be asked intelligibly about reality as a whole (including God), but only about parts of it. As regards the teleological explanation, it usually arrives, before long, at a Creator, or at least an Artificer, whose purposes are realized in the course of nature. But if a man is so obstinately teleological as to continue to ask what purpose is served by the Creator, it becomes obvious that his question is impious. It is, moreover, unmeaning, since, to make it significant, we should have to suppose the Creator created by some super-Creator whose purposes He served. The conception of purpose, therefore, is only applicable within reality, not to reality as a whole.
A not dissimilar argument applies to mechanistic explanations. One event is caused by another, the other by a third, and so on. But if we ask for a cause of the whole, we are driven again to the Creator, who must Himself be uncaused. All causal explanations, therefore must have an arbitrary beginning. That is why it is no defect in the theory of the atomists to have left the original movements of the atoms unaccounted for.
It must not be supposed that their reasons for their theories