And first with regard to the senses.

We do and we must suppose, that as the conformation of their organs are nearly or altogether the same in all men, so the manner of perceiving external objects is in all men the same, or with little difference.

We are satisfied that what appears to be light to one eye, appears light to another; that what seems sweet to one palate, is sweet to another; that what is dark and bitter to this man, is likewise dark and bitter to that; and we conclude in the same manner of great and little, hard and soft, hot and cold, rough and smooth; and indeed of all the natural qualities and affections of bodies.

If we suffer ourselves to imagine, that their senses present to different men different images of things, this sceptical proceeding will make every sort of reasoning on every subject vain and frivolous, even that sceptical reasoning itself which had persuaded us to entertain a doubt concerning the agreement of our perceptions.

But as there will be little doubt that bodies present similar images to the whole species, it must necessarily be allowed, that the pleasures and the pains which every object excites in one man, it must raise in all mankind, whilst it operates naturally, simply, and by its proper powers only: for if we deny this, we must imagine that the same cause, operating in the same manner, and on subjects of the same kind, will produce different effects; which would be highly absurd.