All that stock of arguments they produce to depreciate our faculties
and make mankind appear ignorant and low, are drawn principally
from this head, namely, that we are under an invincible blindness
as to the true and real nature of things. This they exaggerate,
and love to enlarge on. We are miserably bantered, say they, by our
senses, and amused only with the outside and show of things. The real
essence, the internal qualities and constitution of every the meanest
object, is hid from our view; something there is in every drop of water,
every grain of sand, which it is beyond the power of human understanding
to fathom or comprehend. But, it is evident from what has been shown that
all this complaint is groundless, and that we are influenced by false
principles to that degree as to mistrust our senses, and think we know
nothing of those things which we perfectly comprehend.

102. One great inducement to our pronouncing ourselves ignorant of the
nature of things is the current opinion that everything includes within
itself the cause of its properties; or that there is in each object an
inward essence which is the source whence its discernible qualities flow,
and whereon they depend. Some have pretended to account for appearances
by occult qualities, but of late they are mostly resolved into mechanical
causes, to wit. the figure, motion, weight, and suchlike qualities, of
insensible particles; whereas, in truth, there is no other agent or
efficient cause than spirit, it being evident that motion, as well as all
other ideas, is perfectly inert. See sect. 25. Hence, to endeavour to
explain the production of colours or sounds, by figure, motion,
magnitude, and the like, must needs be labour in vain. And accordingly we
see the attempts of that kind are not at all satisfactory. Which may be
said in general of those instances wherein one idea or quality is
assigned for the cause of another. I need not say how many hypotheses and
speculations are left out, and how much the study of nature is abridged