them only which are most immediately connected with the subject of my Essay.

In the first place, There is a manifest ambiguity in the phrase Necessary connec-, tion. This indeed is acknowledged by Mr HUME himself; but is not sufficiently confidered and explained by him,

The phrafe Neceffary connection may be fuppofed to mean a connection which from the nature of things must take place, or, more accurately speaking, according to the laws of human thought, must be conceived by us to take place; the contrary of it, or any fuppofition inconsistent with it, being not merely falfe, but either intuitively or demonftrably impoffible and abfurd. Of this nature are all the relations in geometry; and many relations in various other fubjects; several of which neceffary relations, though of the highest importance in fcientific investigations, have never yet been confidered with that attention which they deferve.

If Mr HUME meant that mankind have

a

a propenfity to believe, that they perceive fomething like a neceffary connection of this kind between the caufe and the effect in the material world, he was certainly mistaken, and deceived by the ambiguity of a word.

The bulk of mankind, far from having fuch a belief, never heard nor ever dreamed of fuch a question or fuch a fuppofition; and I fufpect it will be found no eafy matter to make them comprehend the question, or understand the difference between a strictly neceffary truth and a merely contingent truth of arbitrary appointment, which might have been otherwife if it had fo pleafed God.

That a few individuals have held that the ultimate facts or laws of phyfics with refpect to the relation of caufe and effect are neceffary truths, as much as thofe of geometry, cannot be difputed. But this is of little confequence in the prefent queftion: For, befides the fmallness of the number of those who have thought that the ultimate facts in physics were either

felf

felf-evident, or demonftrable a priori as neceffary truths, there can be no doubt, that fuch an opinion, whether right or wrong, is the result of deep inquiry and reafoning: but the bulk of mankind have never been accustomed to inquire or reafon on fuch fubjects.

we may

Though we have no reason to believe, for once, and for the sake of the argument to which the hypothefis leads, suppose, with Mr HUME, that mankind in general have conceived fome strictly neceffary connection between particular caufes and their effects in phyfics, and that, feeling no fuch necessary connection between their own voluntary determinations and actions and the motives of them, they have thence been led to think, that the relation of Caufe and Effect and that of Motive and Action were different, and that the former being necessary, and the latter not, voluntary agents had a kind of power or liberty in their actions which bodies had not with respect to the changes which occur in them.

It must be observed, that this would be a very strange and falfe inference from the supposed premifes: For furely fnow would melt with heat, a stone, when unsupported, would fall to the ground, and a billiard-ball would move on being struck, with equal certainty, and with equally little pretenfions to liberty, whether the three phyfical laws alluded to in these three instances of caufe and effect be neceffary truths, like those of geometry, or only contingent truths of pofitive appointment, according to the will of the Supreme Being, ordering what he faw to be best. Nor would the cafe be different with respect to Motives and Actions, if the same relation, not of neceffity, but only conftant conjunction, were conceived to fubfift between them.

But admitting, in compliment to Mr HUME, that all mankind believed what not one in ten thousand of them ever thought of, and that all of them with one confent drew from what they fo believed an inference fo palpably falfe, that it is fcarce credible that any one individual D fhould

fhould have drawn it, or thought of it; then I think it follows neceffarily, that when ever a perfon is fatisfied that there is not, or even that he has no reafon to think that there is, any fuch neceffary connection between particular phyfical caufes and their effects, he muft inftantly become a convert to the doctrine of Neceffity as explained and afferted by Mr HUME, in his reconciling project. For there would then be left no difference perceptible to him, or even conceivable by him, between the two relations which he was wont to diftinguifh. But this conclufion, which is an evidently neceffary inference from Mr HUME's doctrine on this point, is experimentally falfe; therefore the doctrine of which it is a neceffary inference muft be erroneous.

The difavowal of any belief of a neceffary connection, perceptible or intelligible to us, between particular phyfical caufes and their effects, feems to be very fully implied in the modern and only fuccefsful way of conducting phyfical inquiries; I mean, by obfervation, experiment, and induction.