The want of exercising it in the full extent of things intelligible is that which weakens and extinguishes this noble faculty in us.Trace it and see whether it be not so.The day laborer in a country village has commonly but a small pittance of knowledge because his ideas and notions have been confined to the narrow bounds of a poor conversation and employment；the low mechanic of a country town does somewhat outdo him；porters and cobblers of great cities surpass them.Acountry gentleman who，leaving Latin and learning in the university，removes thence to his mansion house and associates with neighbors of the same strain，who relish nothing but hunting and a bottle?with those alone he spends his time，with those alone he converses and can away with no company whose discourse goes beyond what claret and dissoluteness inspire.Such a patriot，formed in this happy way of improvement，cannot fail，as you see，to give notable decisions upon the bench at quarter sessions and eminent proofs of his skill in politics，when the strength of his purse and party have advanced him to a more conspicuous station.To such a one truly an ordinary coffee-house cleaner of the city is an errant statesman，and as much superior to，as a man conversant about Whitehall and the Court is to an ordinary shopkeeper.To carry this a little further.Here is one muffled up in the zeal and infallibility of his own sect and will not touch a book or enter into debate with a person that will question any of those things which to him are sacred.Another surveys our differences in religion with an equitable and fair indifference，and so finds probably that none of them are in everything unexceptionable.
These decisions and systems were made by men and carry the mark of fallible on them；and in those whom he differs from，and till he opened his eyes had a general prejudice against，he meets with more to be said for a great many things than before he was aware of or could have imagined.Which of these two now is most likely to judge right in our religious controversies and to be most stored with truth，the mark all pretend to aim at？All these men that I have instanced in，thus unequally furnished with truth and advanced in knowledge，I suppose of equal natural parts；all the odds between them has been the different scope that has been given to their understandings to range in，for the gathering up of information and furnishing their heads with ideas，notions and observations whereon to employ their minds and form their understandings.
It will possibly be objected，Who is sufficient for all this？
I answer，more than can be imagined.Everyone knots what his proper business is and what，according to the character he makes of himself，the world may justly expect of him；and to answer that，he will find he will have time and opportunity enough to furnish himself，if he will not deprive himself by a narrowness of spirit of those helps that are at hand.I do not say to be a good geographer that a man should visit every mountain，river，promontory and creel；upon the face of the earth，view the buildings and survey the land everywhere，as if he were going to make a purchase.But yet everyone must allow that he shall know a country better that makes often sallies into it and traverses it up and down than he that，like a mill-horse，goes still round in the same tract or keeps within the narrow bounds of a field or two that delight him.He that will enquire out the best books in every science and inform himself of the most material authors of the several sects of philosophy and religion，will not find it an infinite work to acquaint himself with the sentiments of mankind concerning the most weighty and comprehensive subjects.Let him exercise the ******* of his reason and understanding in such a latitude as this，and his mind will be strengthened，his capacity enlarged，his faculties improved；and the light which the remote and scattered parts of truth will give to one another still so assist his judgment，that he will seldom be widely out or miss giving proof of a clear head and a comprehensive knowledge.
At least，this is the only way I know to give the understanding its due improvement to the full extent of its capacity，and to distinguish the two most different things I know in the world，a logical chicaner from a man of reason.Only，he that would thus give the mind its flight and send abroad his enquiries into all parts after truth must be sure to settle in his head determined ideas of all that he employs his thoughts about，and never fail to judge himself and judge unbiasedly of all that he receives from others either in their writings or discourses.Reverence or prejudice must not be suffered to give beauty or deformity to any of their opinions.