After all, I may, perhaps, agree to your general Conclusion in favour of Liberty, tho' upon different Premises from those, on which you endeavour to found it. I think the State ought to tolerate every Principle of Philosophy; nor is there an Instance of any Government's suffering in its political Interests by such Indulgence. There is no Enthusiasm among Philosophers; their Doctrines are not very alluring to the People; and no Restraint can be put upon their Reasonings, but what must be of dangerous Consequence to the Sciences, and even to the State, by paving the Way for Persecution and Oppression in Points, wherein the Generality of Mankind are more deeply interested and concern'd.
But there occurs to me, (continu'd I) with regard to your main Topic a Difficulty, which I shall just propose to you, without insisting on it, lest it lead into Reasonings of too nice and delicate a Nature. In a Word, I much doubt, whether it be possible for a Cause to be known only by its Effect (as you have all along suppos'd) or to be of so singular and particular a Nature as to have no Parallel and no Similarity with any other Cause or Object, that has ever fallen under our Observation. 'Tis only when two Species of Objects are found to be constantly conjoin'd, that we can infer the one from the other; and were an Effect presented, which was entirely singular, and could notbe
