orce to believe the existence of a like cause. It is
needless in my opinion to illustrate this argument by the enumeration
of particulars. The smallest attention will supply us with more than are
requisite. The resemblance betwixt the actions of animals and those
of men is so entire in this respect, that the very first action of
the first animal we shall please to pitch on, will afford us an
incontestable argument for the present doctrine.

This doctrine is as useful as it is obvious, and furnishes us with a
kind of touchstone, by which we may try every system in this species
of philosophy. It is from the resemblance of the external actions of
animals to those we ourselves perform, that we judge their internal
likewise to resemble ours; and the same principle of reasoning, carryd
one step farther, will make us conclude that since our internal actions
resemble each other, the causes, from which they are derivd, must also
be resembling. When any hypothesis, therefore, is advancd to explain a
mental operation, which is common to men and beasts, we must apply the
same hypothesis to both; and as every true hypothesis will abide this
trial, so I may venture to affirm, that no false one will ever be able
to endure it. The common defect of those systems, which philosophers
have employd to account for the actions of the mind, is, that they
suppose such a subtility and refinement of thought, as not only exceeds
the capacity of mere animals, but even of children and the common people
in our own species; who are notwithstanding susceptible of the same
emotions and affections as persons of the most accomplishd genius and
understanding. Such a subtility is a dear proof of the falshood, as the
contrary simplicity of the truth, of any system.

Let us therefore put our present system concerning the nature of the
understanding to this decisive trial, and see whether it will equally
account for the reasonings of beasts as for these of the human species.

Here we must make a distinction betwixt those actions of animals, which
are of a vulgar nature, and seem to be on a level with their common
capacities, and those more extraordinary instances of sagacity, which
they sometimes discover for their own preservation, and the propagation
of their species. A dog, that avoids fire and precipices, that shuns
strangers, and caresses his master, affords us an instance of the first
kind. A bird, that chooses with such care and nicety the place and
m