nd angles of a
diagram, should be bigger one than the other, and yet doubt of the
existence of those lines and angles, which by looking on he makes use of
to measure that by.

7. IV. Fourthly, Because our Senses assist one another's Testimony of
the Existence of outward Things, and enable us to predict.

Our SENSES in many cases BEAR WITNESS TO THE TRUTH OF EACH OTHER'S
REPORT, concerning the existence of sensible things without us. He that
SEES a fire, may, if he doubt whether it be anything more than a bare
fancy, FEEL it too; and be convinced, by putting his hand in it. Which
certainly could never be put into such exquisite pain by a bare idea or
phantom, unless that the pain be a fancy too: which yet he cannot, when
the burn is well, by raising the idea of it, bring upon himself again.

Thus I see, whilst I write this, I can change the appearance of the
paper; and by designing the letters, tell BEFOREHAND what new idea it
shall exhibit the very next moment, by barely drawing my pen over it:
which will neither appear (let me fancy as much as I will) if my hands
stand still; or though I move my pen, if my eyes be shut: nor, when
those characters are once made on the paper, can I choose afterwards but
see them as they are; that is, have the ideas of such letters as I have
made. Whence it is manifest, that they are not barely the sport and play
of my own imagination, when I find that the characters that were made at
the pleasure of my own thoughts, do not obey them; nor yet cease to be,
whenever I shall fancy it, but continue to affect my senses constantly
and regularly, according to the figures I made them. To which if we will
add, that the sight of those shall from another man, draw such sounds as
I beforehand design they shall stand for, there will be little reason
left to doubt that those words I write do really exist without me, when
they cause a long series of regular sounds to affect my ears, which
could not be the effect of my imagination, nor could my memory retain
them in that order.

8. This Certainty is as great as our Condition needs.

But yet, if after all this any one will be so sceptical as to distrust
his senses, and to affirm that all we see and hear, feel and taste,
think and do, during our whole being, is but the series and deluding
appearances of a long dream, whereof there is no reality; and therefore
will question the existence of all things, or our knowledge of anything:
I must desire hi