often requires that we should enlarge our views of them; and there is no commoner error in private effort or in legislation than to aim at some obvious good, whilst overlooking other consequences of our action, the evil of which may far outweigh that good.  An important consequence of eating is to satisfy hunger, and this is the ordinary motive to eat; but it is a poor account of the physiological consequences.  An important consequence of firing a gun is the propulsion of the bullet or shell; but there are many other consequences in the whole effect, and one of them is the heating of the barrel, which, accumulating with rapid firing, may at last put the gun out of action.  The tides have consequences to shipping and in the wear and tear of the coast that draw every one’s attention; but we are told that they also retard the rotation of the earth, and at last may cause it to present always the same face to the sun, and, therefore, to be uninhabitable.  Such concurrent consequences of any cause may be called its Co-effects:  the Effect being the sum of them.

The neglect to take account of the whole effect (that is, of all the co-effects) in any case of causation is perhaps the reason why many philosophers have maintained the doctrine of a “Plurality of Causes”:  meaning not that more than one condition is operative in the antecedent of every event (which is true), but that the same event may be due at different times to different antecedents, that in fact there may be vicarious causes.  If, however, we take any effect as a whole, this does not seem to be true.  A fire may certainly be lit in many ways:  with a match or a flint and steel, or by rubbing sticks together, or by a flash of lightning:  have we not here a plurality of causes?  Not if we take account of the whole effect; for then we shall find it modified in each case according to the difference of the cause.  In one case there will be a burnt match, in another a warm flint, in the last a changed state of electrical tension.  And similar differences are found in cases of death under different conditions, as stabbing, hanging, cholera; or of shipwreck from explosion, scuttling, tempest.  Hence a Coroner’s Court expects to find, by examining a corpse, the precise cause of death.  In short, if we knew the facts minutely enough, it would be found that there is only one Cause (sum of conditions) for each Effect (sum of co-effects), and that the order of events is as uniform backwards as forwards.

Still, as we are far from knowing events minutely, it is necessary in practical affairs, and even in the more complex and unmanageable scientific investigations, especially those that deal with human life, to acknowledge a possible plurality of causes for any effect.  Indeed, forgetfulness of this leads to many rash generalisations; as that ‘revolutions always begin in hunger’; or that ’myths are a disease of language.’  Then there is great waste of ingenuity in reconciling such propositions with the recalcitrant facts.  A scientific method recognises that there may be other causes of effects thus vaguely conceived, and then proceeds to distinguish in each class of effects the peculiarities due to different causes.