All sceptics pretend, that, if reason be considered in an abstract view, it furnishes invincible arguments against itself; and that we could never retain any conviction or assurance, on any subject, were not the sceptical reasonings so refined and subtle, that they are not able to counterpoise the more solid and more natural arguments derived from the senses and experience.  But it is evident, whenever our arguments lose this advantage, and run wide of common life, that the most refined scepticism comes to be upon a footing with them, and is able to oppose and counterbalance them.  The one has no more weight than the other.  The mind must remain in suspense between them; and it is that very suspense or balance, which is the triumph of scepticism.

But I observe, says cleanthes, with regard to you, Philo, and all speculative sceptics, that your doctrine and practice are as much at variance in the most abstruse points of theory as in the conduct of common life.  Wherever evidence discovers itself, you adhere to it, notwithstanding your pretended scepticism; and I can observe, too, some of your sect to be as decisive as those who make greater professions of certainty and assurance.  In reality, would not a man be ridiculous, who pretended to reject NEWTON’s explication of the wonderful phenomenon of the rainbow, because that explication gives a minute anatomy of the rays of light; a subject, forsooth, too refined for human comprehension?  And what would you say to one, who, having nothing particular to object to the arguments of Copernicus and Galileo for the motion of the earth, should withhold his assent, on that general principle, that these subjects were too magnificent and remote to be explained by the narrow and fallacious reason of mankind?

There is indeed a kind of brutish and ignorant scepticism, as you well observed, which gives the vulgar a general prejudice against what they do not easily understand, and makes them reject every principle which requires elaborate reasoning to prove and establish it.  This species of scepticism is fatal to knowledge, not to religion; since we find, that those who make greatest profession of it, give often their assent, not only to the great truths of Theism and natural theology, but even to the most absurd tenets which a traditional superstition has recommended to them.  They firmly believe in witches, though they will not believe nor attend to the most simple proposition of Euclid.  But the refined and philosophical sceptics fall into an inconsistence of an opposite nature.  They push their researches into the most abstruse corners of science; and their assent attends them in every step, proportioned to the evidence which they meet with.  They are even obliged to acknowledge, that the most abstruse and remote objects are those which are best explained by philosophy.  Light is in reality anatomised.  The true system of the heavenly bodies is discovered and ascertained.