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.  Let us first consider this point in the sense of taste, and the rather as the faculty in question has taken its name from that sense.  All men are agreed to call vinegar sour, honey sweet, and aloes bitter; and as they are all agreed in finding those qualities in those objects, they do not in the least differ concerning their effects with regard to pleasure and pain.  They all concur in calling sweetness pleasant, and sourness and bitterness unpleasant.  Here there is no diversity in their sentiments; and that there is not, appears fully from the consent of all men in the metaphors which are taken, from the souse of taste.  A sour temper, bitter expressions, bitter curses, a bitter fate, are terms well and strongly understood by all.  And we are altogether as well understood when we say, a sweet disposition, a sweet person, a sweet condition and the like.  It is confessed, that custom and some other causes have made many deviations from the natural pleasures or pains which belong to these several tastes; but then the power of distinguishing between the natural and the acquired relish remains to the very last.  A man frequently comes to prefer the taste of tobacco to that of sugar, and the flavor of vinegar to that of milk; but this makes no confusion in tastes, whilst he is sensible that the tobacco and vinegar are not sweet, and whilst he knows that habit alone has reconciled his palate to these alien pleasures.  Even with such a person we may speak, and with sufficient precision, concerning tastes.  But should any man be found who declares, that to him tobacco has a taste like sugar, and that he cannot distinguish between milk and vinegar; or that tobacco and vinegar are sweet, milk bitter, and sugar sour; we immediately conclude that the organs of this man are out of order, and that his palate is utterly vitiated.