We are born to be, if we please, rational creatures, but it is use and exercise only that makes us so, and we are indeed so no farther than industry … - John Locke

The understanding, like the eye, whilst it makes us see and perceive all other things, takes no notice of itself: and it requires art and pains to set it at a distance and make it its own object....

If by this inquiry into the nature of the understanding, I can discover the powers thereof; how far they reach; to what things they are in any degree proportionate; and where they fail us, I suppose it may be of use to prevail with the busy mind of man to be more cautious in meddling with things exceeding its comprehension; to stop when it is at the utmost extent of its tether; and to sit down in a quiet ignorance of those things which, upon examination, are found to be beyond the reach of our capacities.

The great question which in all ages has disturbed mankind, and brought on them the greatest part of those mischiefs which have ruined cities, depopulated countries, and disordered the peace of the world, has been, not whether there be power in the world, nor whence it came, but who should have it.

The power of the legislative, being derived from the people by a positive voluntary grant and institution, can be no other than what that positive grant conveyed, which being only to make laws, and not to make legislators, the legislative can have no power to transfer their authority of making laws, and place it in other hands.