630 Onthe Method of judging by the Ear 
Moreover, we will take for granted, what 
will be afterwards proved; namely, that the 
pulses of air, proceeding from the vibrating 
surface, will strike the right ear, which is turned 
towards it, more forcibly than the left. Under 
these circumstances, two cotemporary currents 
of the same sound will strike the opposite 
sides of his head, at the same time, with unequal 
momenta: he is therefore left to form a judg- 
ment of the incidents; and the sensibility in 
question enables him to determine with certainty, 
which of his ears is most affected. A thousand 
similar cases have occurred in the course of 
his life, in which he has been convinced by 
the testimony of his eyes and hands, that the 
strongest impression is constantly made on that 
ear which is turned towards the sounding 
body; he therefore draws the same conclusion 
in those cases where he is not assisted by the 
evidence of sight and touch. In this manner 
every man acquires a practical rule, which, like 
all practical rules formed in infancy, becomes 
a mechanical action, and is therefore exercised . 
by every body, while very few understand the 
nature of it. Some of my readers may suspect, 
that on the present theory, too much influence 
is ascribed to experience. But such a suspi- 
cion would in my opinion be ill founded ; for, 
all the senses have their practical maxims, which 
